Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad...
Transcript of Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad...
![Page 1: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/1.jpg)
Tracing Information Flows Between Ad ExchangesUsing Retargeted Ads
Muhammad Ahmad Bashir, Sajjad Arshad, William Robertson, Christo Wilson
Northeastern University
![Page 2: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/2.jpg)
Your Privacy Footprint
2
![Page 3: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/3.jpg)
Your Privacy Footprint
2
![Page 4: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/4.jpg)
Your Privacy Footprint
2
![Page 5: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/5.jpg)
Your Privacy Footprint
2
![Page 6: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/6.jpg)
Your Privacy Footprint
2
![Page 7: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/7.jpg)
Your Privacy Footprint
2
![Page 8: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/8.jpg)
Real Time Bidding
3
![Page 9: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/9.jpg)
Real Time Bidding
• RTB brings more flexibility in the ad ecosystem.• Ad request managed by an Ad Exchange which holds an auction.
• Advertisers bid on each ad impression.
3
![Page 10: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/10.jpg)
Real Time Bidding
• RTB brings more flexibility in the ad ecosystem.• Ad request managed by an Ad Exchange which holds an auction.
• Advertisers bid on each ad impression.
3
Exchange Advertiser
Cookie matching is a prerequisite.
![Page 11: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/11.jpg)
Real Time Bidding
• RTB brings more flexibility in the ad ecosystem.• Ad request managed by an Ad Exchange which holds an auction.
• Advertisers bid on each ad impression.
• RTB spending to cross $20B by 2017[1].• 49% annual growth.
• Will account for 80% of US Display Ad spending by 2022.
3
[1] http://www.prnewswire.com/news-releases/new-idc-study-shows-real-time-bidding-rtb-display-ad-spend-to-grow-worldwide-to-208-billion-by-2017-228061051.html
Exchange Advertiser
Cookie matching is a prerequisite.
![Page 12: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/12.jpg)
4
User Publisher Ad Exchange Advertisers
![Page 13: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/13.jpg)
4
GET, CNN’s Cookie
User Publisher Ad Exchange Advertisers
![Page 14: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/14.jpg)
4
GET, CNN’s Cookie
GET, DoubleClick’s Cookie
User Publisher Ad Exchange Advertisers
![Page 15: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/15.jpg)
4
GET, CNN’s Cookie
GET, DoubleClick’s Cookie
User Publisher Ad Exchange Advertisers
Solicit bids, DoubleClick’s Cookie
Bid
![Page 16: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/16.jpg)
Real Time Bidding (RTB)
4
GET, CNN’s Cookie
GET, DoubleClick’s Cookie
User Publisher Ad Exchange Advertisers
Solicit bids, DoubleClick’s Cookie
Bid
![Page 17: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/17.jpg)
Real Time Bidding (RTB)
4
GET, CNN’s Cookie
GET, DoubleClick’s Cookie
User Publisher Ad Exchange Advertisers
Solicit bids, DoubleClick’s Cookie
GET, RightMedia’s Cookie
Advertisement
Bid
![Page 18: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/18.jpg)
Real Time Bidding (RTB)
4
GET, CNN’s Cookie
GET, DoubleClick’s Cookie
User Publisher Ad Exchange Advertisers
Solicit bids, DoubleClick’s Cookie
GET, RightMedia’s Cookie
Advertisement
Bid
Advertisers cannot read their cookie!
![Page 19: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/19.jpg)
Cookie Matching
Key problem: Advertisers cannot read their cookies in the RTB auction• How can they submit reasonable bids if they cannot identify the user?
Solution: cookie matching• Also known as cookie synching
• Process of linking the identifiers used by two ad exchanges
5
![Page 20: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/20.jpg)
Cookie Matching
Key problem: Advertisers cannot read their cookies in the RTB auction• How can they submit reasonable bids if they cannot identify the user?
Solution: cookie matching• Also known as cookie synching
• Process of linking the identifiers used by two ad exchanges
5
GET, Cookie=12345
301 Redirect, Location=http://criteo.com/?dblclk_id=12345
![Page 21: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/21.jpg)
Cookie Matching
Key problem: Advertisers cannot read their cookies in the RTB auction• How can they submit reasonable bids if they cannot identify the user?
Solution: cookie matching• Also known as cookie synching
• Process of linking the identifiers used by two ad exchanges
5
GET, Cookie=12345
301 Redirect, Location=http://criteo.com/?dblclk_id=12345
![Page 22: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/22.jpg)
Cookie Matching
Key problem: Advertisers cannot read their cookies in the RTB auction• How can they submit reasonable bids if they cannot identify the user?
Solution: cookie matching• Also known as cookie synching
• Process of linking the identifiers used by two ad exchanges
5
GET, Cookie=12345
GET ?dblclk_id=12345, Cookie=ABCDE
301 Redirect, Location=http://criteo.com/?dblclk_id=12345
![Page 23: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/23.jpg)
Cookie Matching
Key problem: Advertisers cannot read their cookies in the RTB auction• How can they submit reasonable bids if they cannot identify the user?
Solution: cookie matching• Also known as cookie synching
• Process of linking the identifiers used by two ad exchanges
5
GET, Cookie=12345
GET ?dblclk_id=12345, Cookie=ABCDE
301 Redirect, Location=http://criteo.com/?dblclk_id=12345
![Page 24: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/24.jpg)
Cookie Matching
Key problem: Advertisers cannot read their cookies in the RTB auction• How can they submit reasonable bids if they cannot identify the user?
Solution: cookie matching• Also known as cookie synching
• Process of linking the identifiers used by two ad exchanges
5
GET, Cookie=12345
GET ?dblclk_id=12345, Cookie=ABCDE
301 Redirect, Location=http://criteo.com/?dblclk_id=12345
![Page 25: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/25.jpg)
Prior Work
• Several studies have examined cookie matching• Acar et al. found hundreds of domains passing identifiers to each other
• Olejnik et al. found 125 exchanges matching cookies
• Falahrastegar et al. analyzed clusters of exchanges that share the exact same cookies
6
![Page 26: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/26.jpg)
Prior Work
• Several studies have examined cookie matching• Acar et al. found hundreds of domains passing identifiers to each other
• Olejnik et al. found 125 exchanges matching cookies
• Falahrastegar et al. analyzed clusters of exchanges that share the exact same cookies
• These studies rely on studying HTTP requests/responses.
6
![Page 27: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/27.jpg)
Challenge 1: Server Side Matching
7
![Page 28: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/28.jpg)
Challenge 1: Server Side Matching
7
1)
Criteo observes the user.
(IP: 207.91.160.7)
![Page 29: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/29.jpg)
Challenge 1: Server Side Matching
7
1)
2)
Criteo observes the user.
(IP: 207.91.160.7)
RightMedia observes the user.
(IP: 207.91.160.7)
![Page 30: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/30.jpg)
Challenge 1: Server Side Matching
7
1)
2)
Criteo observes the user.
(IP: 207.91.160.7)
RightMedia observes the user.
(IP: 207.91.160.7)
Behind the scene, RightMedia and Criteo sync up.
(IP: 207.91.160.7)
![Page 31: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/31.jpg)
Challenge 2: Obfuscation
8
![Page 32: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/32.jpg)
Challenge 2: Obfuscation
8
![Page 33: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/33.jpg)
Challenge 2: Obfuscation
8
amazon.com
![Page 34: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/34.jpg)
Challenge 2: Obfuscation
8
amazon.com
dbclk.js
![Page 35: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/35.jpg)
Challenge 2: Obfuscation
8
GET %^$ck#&93#&, Cookie=XYZYX
amazon.com
dbclk.js
![Page 36: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/36.jpg)
Challenge 2: Obfuscation
8
GET %^$ck#&93#&, Cookie=XYZYX
amazon.com
dbclk.js
![Page 37: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/37.jpg)
Challenge 2: Obfuscation
8
GET %^$ck#&93#&, Cookie=XYZYX
amazon.com
dbclk.js
![Page 38: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/38.jpg)
Challenge 2: Obfuscation
8
GET %^$ck#&93#&, Cookie=XYZYX
amazon.com
dbclk.js
![Page 39: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/39.jpg)
Challenge 2: Obfuscation
8
GET %^$ck#&93#&, Cookie=XYZYX
amazon.com
dbclk.js
![Page 40: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/40.jpg)
Goal
Develop a method to identify information flows (cookie matching) between ad exchanges
• Mechanism agnostic: resilient to obfuscation
• Platform agnostic: detect sharing on the client- and server-side
9
![Page 41: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/41.jpg)
Goal
Develop a method to identify information flows (cookie matching) between ad exchanges
• Mechanism agnostic: resilient to obfuscation
• Platform agnostic: detect sharing on the client- and server-side
9
?
![Page 42: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/42.jpg)
Key Insight: Use Retargeted Ads
Retargeted ads are the most highly targeted form of online ads
10
$15.99
![Page 43: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/43.jpg)
Key Insight: Use Retargeted Ads
Retargeted ads are the most highly targeted form of online ads
10
$15.99
![Page 44: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/44.jpg)
Key Insight: Use Retargeted Ads
Retargeted ads are the most highly targeted form of online ads
10
Key insight: because retargets are so specific, they can be used to conduct controlled experiments
• Information must be shared between ad exchanges to serve retargeted ads
$15.99
![Page 45: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/45.jpg)
Contributions
1. Novel methodology for identifying information flows between ad exchanges
2. Demonstrate the impact of ad network obfuscation in practice• 31% of cookie matching partners cannot be identified using heuristics
3. Develop a method to categorize information sharing relationships
4. Use graph analysis to infer the roles of actors in the ad ecosystem
11
![Page 46: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/46.jpg)
Contributions
1. Novel methodology for identifying information flows between ad exchanges
2. Demonstrate the impact of ad network obfuscation in practice• 31% of cookie matching partners cannot be identified using heuristics
3. Develop a method to categorize information sharing relationships
4. Use graph analysis to infer the roles of actors in the ad ecosystem
11
![Page 47: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/47.jpg)
Data CollectionClassifying Ad Network FlowsResults
12
![Page 48: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/48.jpg)
Using Retargets as an Experimental Tool
13
Key observation: retargets are only served under very specific circumstances
1)
![Page 49: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/49.jpg)
Using Retargets as an Experimental Tool
13
Key observation: retargets are only served under very specific circumstances
1)Advertiser observes the user at a shop
![Page 50: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/50.jpg)
Using Retargets as an Experimental Tool
13
Key observation: retargets are only served under very specific circumstances
1)
2)
Advertiser observes the user at a shop
![Page 51: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/51.jpg)
Using Retargets as an Experimental Tool
13
Key observation: retargets are only served under very specific circumstances
1)
2)
Advertiser observes the user at a shop
Advertiser and the exchange must have matched cookies
![Page 52: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/52.jpg)
Using Retargets as an Experimental Tool
This implies a causal flow of information from Exchange Advertiser
13
Key observation: retargets are only served under very specific circumstances
1)
2)
Advertiser observes the user at a shop
Advertiser and the exchange must have matched cookies
![Page 53: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/53.jpg)
Data Collection Overview
14
![Page 54: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/54.jpg)
Data Collection Overview
14
Single Persona10 websites/persona 10 products/website
Visit Persona
![Page 55: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/55.jpg)
Data Collection Overview
14
150 Publishers15 pages/publisher
Single Persona10 websites/persona 10 products/website
Visit Persona Visit Publishers
![Page 56: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/56.jpg)
Data Collection Overview
14
150 Publishers15 pages/publisher
Single Persona10 websites/persona 10 products/website
Visit Persona Visit Publishers
Store Images,Inclusion Chains,HTTP requests/
responses
571,636 Images
![Page 57: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/57.jpg)
Data Collection Overview
14
150 Publishers15 pages/publisher
Single Persona10 websites/persona 10 products/website
Visit Persona Visit Publishers
Store Images,Inclusion Chains,HTTP requests/
responses
571,636 Images
![Page 58: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/58.jpg)
Data Collection Overview
14
150 Publishers15 pages/publisher
Single Persona10 websites/persona 10 products/website
Visit Persona Visit Publishers
Store Images,Inclusion Chains,HTTP requests/
responses
90
Pe
rso
nas
571,636 Images
{
![Page 59: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/59.jpg)
Data Collection Overview
14
150 Publishers15 pages/publisher
Single Persona10 websites/persona 10 products/website
Visit Persona Visit Publishers
Store Images,Inclusion Chains,HTTP requests/
responsesPotential Targeted
Ads31,850
Ad Detection
Filter Images which appeared in > 1 persona
90
Pe
rso
nas
571,636 Images
{
![Page 60: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/60.jpg)
Data Collection Overview
14
150 Publishers15 pages/publisher
Single Persona10 websites/persona 10 products/website
Visit Persona Visit Publishers
Store Images,Inclusion Chains,HTTP requests/
responsesPotential Targeted
Ads31,850
Ad DetectionIsolated Retargeted Ads
Filter Images which appeared in > 1 persona
90
Pe
rso
nas
571,636 Images
Crowd Sourcing
{
![Page 61: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/61.jpg)
Crowd Sourcing
15
We used Amazon Mechanical Turk (AMT) to label 31,850 ads.
![Page 62: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/62.jpg)
Crowd Sourcing
15
We used Amazon Mechanical Turk (AMT) to label 31,850 ads.
• Total 1,142 Tasks.
• 30 ads / Task.
• 27 unlabeled.
• 3 labeled by us.
• 2 workers per ad.
• $415 spent.
![Page 63: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/63.jpg)
Crowd Sourcing
15
We used Amazon Mechanical Turk (AMT) to label 31,850 ads.
• Total 1,142 Tasks.
• 30 ads / Task.
• 27 unlabeled.
• 3 labeled by us.
• 2 workers per ad.
• $415 spent.
![Page 64: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/64.jpg)
Crowd Sourcing
15
We used Amazon Mechanical Turk (AMT) to label 31,850 ads.
• Total 1,142 Tasks.
• 30 ads / Task.
• 27 unlabeled.
• 3 labeled by us.
• 2 workers per ad.
• $415 spent.
![Page 65: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/65.jpg)
Crowd Sourcing
15
We used Amazon Mechanical Turk (AMT) to label 31,850 ads.
• Total 1,142 Tasks.
• 30 ads / Task.
• 27 unlabeled.
• 3 labeled by us.
• 2 workers per ad.
• $415 spent.
![Page 66: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/66.jpg)
Final Dataset
5,102 unique retargeted ads• From 281 distinct online retailers
35,448 publisher-side chains that served the retargets• We observed some retargets multiple times
16
![Page 67: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/67.jpg)
Data CollectionClassifying Ad Network FlowsResults
17
![Page 68: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/68.jpg)
A look at Publisher Chains
18
![Page 69: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/69.jpg)
A look at Publisher Chains
18
Exam
ple
Publisher-side chain
![Page 70: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/70.jpg)
A look at Publisher Chains
18
Exam
ple
Shopper-side chain Publisher-side chain
![Page 71: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/71.jpg)
A look at Publisher Chains
18
Exam
ple
Shopper-side chain Publisher-side chain
• How does Criteo know to serve ad on BBC?
![Page 72: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/72.jpg)
A look at Publisher Chains
18
Exam
ple
Shopper-side chain Publisher-side chain
• How does Criteo know to serve ad on BBC?• In this case it is pretty trivial.• Criteo observed us on the shopper.
![Page 73: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/73.jpg)
A look at Publisher Chains
18
Exam
ple
Shopper-side chain Publisher-side chain
• How does Criteo know to serve ad on BBC?• In this case it is pretty trivial.• Criteo observed us on the shopper.
• Can we classify all such publisher-side chains?
![Page 74: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/74.jpg)
What is a Chain?
19
![Page 75: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/75.jpg)
What is a Chain?
19
![Page 76: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/76.jpg)
What is a Chain?
19
![Page 77: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/77.jpg)
What is a Chain?
19
![Page 78: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/78.jpg)
What is a Chain?
19
![Page 79: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/79.jpg)
What is a Chain?
19
![Page 80: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/80.jpg)
What is a Chain?
19
![Page 81: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/81.jpg)
What is a Chain?
19
![Page 82: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/82.jpg)
What is a Chain?
19
![Page 83: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/83.jpg)
What is a Chain?
19
![Page 84: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/84.jpg)
What is a Chain?
19
![Page 85: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/85.jpg)
What is a Chain?
19
a
a
e
e
![Page 86: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/86.jpg)
What is a Chain?
19
^pub .* e a$
a
a
e
e
![Page 87: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/87.jpg)
Four Classifications
Four possible ways for a retargeted ad to be served 1. Direct (Trivial) Matching
2. Cookie Matching
3. Indirect Matching
4. Latent (Server-side) Matching
20
![Page 88: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/88.jpg)
Four Classifications
Four possible ways for a retargeted ad to be served 1. Direct (Trivial) Matching
2. Cookie Matching
3. Indirect Matching
4. Latent (Server-side) Matching
20
![Page 89: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/89.jpg)
1) Direct (Trivial) Matching
21
Shopper-side Publisher-side
Exam
ple
Ru
le
![Page 90: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/90.jpg)
1) Direct (Trivial) Matching
21
Shopper-side Publisher-side
Exam
ple
Ru
le ^shop .* a .*$ ^pub a$
![Page 91: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/91.jpg)
1) Direct (Trivial) Matching
21
Shopper-side Publisher-side
Exam
ple
Ru
le ^shop .* a .*$ ^pub a$
a is the advertiser that
serves the retarget
![Page 92: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/92.jpg)
1) Direct (Trivial) Matching
21
Shopper-side Publisher-side
Exam
ple
Ru
le ^shop .* a .*$ ^pub a$
a is the advertiser that
serves the retarget
a must appear on the shopper-
side…
… but other trackers may also appear
![Page 93: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/93.jpg)
2) Cookie Matching
22
Shopper-side Publisher-side
Exam
ple
Ru
le
![Page 94: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/94.jpg)
2) Cookie Matching
22
Shopper-side Publisher-side
Exam
ple
Ru
le ^shop .* a .*$ ^pub .* e a$
![Page 95: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/95.jpg)
2) Cookie Matching
22
Shopper-side Publisher-side
Exam
ple
Ru
le ^shop .* a .*$ ^pub .* e a$
e precedes a, which implies an
RTB auction
![Page 96: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/96.jpg)
2) Cookie Matching
22
Shopper-side Publisher-side
Exam
ple
Ru
le ^shop .* a .*$
a must appear on the
shopper-side
^pub .* e a$
e precedes a, which implies an
RTB auction
![Page 97: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/97.jpg)
2) Cookie Matching
22
Shopper-side Publisher-side
Exam
ple
Ru
le ^shop .* a .*$
a must appear on the
shopper-side
^pub .* e a$^* .* e a .*$
Anywhere
e precedes a, which implies an
RTB auction
Transition ea is where cookie match occurs
![Page 98: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/98.jpg)
3) Latent (Server-side) Matching
23
Shopper-side Publisher-side
Exam
ple
Ru
le
![Page 99: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/99.jpg)
3) Latent (Server-side) Matching
23
Shopper-side Publisher-side
Exam
ple
Ru
le ^shop [^ea]$ ^pub .* e a$
![Page 100: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/100.jpg)
3) Latent (Server-side) Matching
23
Shopper-side Publisher-side
Exam
ple
Ru
le ^shop [^ea]$
Neither e nor aappears on the shopper-side
^pub .* e a$
![Page 101: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/101.jpg)
3) Latent (Server-side) Matching
23
Shopper-side Publisher-side
Exam
ple
Ru
le ^shop [^ea]$
Neither e nor aappears on the shopper-side
^pub .* e a$
a must receive information from some shopper-side tracker
![Page 102: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/102.jpg)
3) Latent (Server-side) Matching
23
Shopper-side Publisher-side
Exam
ple
Ru
le ^shop [^ea]$
Neither e nor aappears on the shopper-side
^pub .* e a$
a must receive information from some shopper-side tracker
We find latent matches in practice!
![Page 103: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/103.jpg)
Data CollectionClassifying Ad Network FlowsResults
24
![Page 104: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/104.jpg)
Categorizing Chains
Type Chains % Chains %
Direct (Trivial) Match 1770 5 8449 24
Cookie Match 25049 71 25873 73
Latent (Server-side) Match 5362 15 343 1
No Match 775 2 183 1
25
ClusteredRaw Chains
![Page 105: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/105.jpg)
Categorizing Chains
Type Chains % Chains %
Direct (Trivial) Match 1770 5 8449 24
Cookie Match 25049 71 25873 73
Latent (Server-side) Match 5362 15 343 1
No Match 775 2 183 1
25
Clustered
Take away:
Raw Chains
![Page 106: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/106.jpg)
Categorizing Chains
Type Chains % Chains %
Direct (Trivial) Match 1770 5 8449 24
Cookie Match 25049 71 25873 73
Latent (Server-side) Match 5362 15 343 1
No Match 775 2 183 1
25
Clustered
Take away:1- As expected, most retargets are due to cookie matching
Raw Chains
![Page 107: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/107.jpg)
Categorizing Chains
Type Chains % Chains %
Direct (Trivial) Match 1770 5 8449 24
Cookie Match 25049 71 25873 73
Latent (Server-side) Match 5362 15 343 1
No Match 775 2 183 1
25
Clustered
Take away:1- As expected, most retargets are due to cookie matching
2- Very small number of chains that cannot be categorized
• Suggests low false positive rate of AMT image labeling task
Raw Chains
![Page 108: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/108.jpg)
Categorizing Chains
Type Chains % Chains %
Direct (Trivial) Match 1770 5 8449 24
Cookie Match 25049 71 25873 73
Latent (Server-side) Match 5362 15 343 1
No Match 775 2 183 1
25
Clustered
Take away:1- As expected, most retargets are due to cookie matching
2- Very small number of chains that cannot be categorized
• Suggests low false positive rate of AMT image labeling task
3- Surprisingly large amount latent matches…
Raw Chains
![Page 109: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/109.jpg)
Categorizing Chains
Type Chains % Chains %
Direct (Trivial) Match 1770 5 8449 24
Cookie Match 25049 71 25873 73
Latent (Server-side) Match 5362 15 343 1
No Match 775 2 183 1
26
Raw ChainsClustered
Chains
Cluster together domains by “owner”• E.g. google.com, doubleclick.com, googlesyndication.com
![Page 110: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/110.jpg)
Categorizing Chains
Type Chains % Chains %
Direct (Trivial) Match 1770 5 8449 24
Cookie Match 25049 71 25873 73
Latent (Server-side) Match 5362 15 343 1
No Match 775 2 183 1
26
Raw ChainsClustered
Chains
Cluster together domains by “owner”• E.g. google.com, doubleclick.com, googlesyndication.com
Latent matches essentially disappear• The vast majority of these chains involve Google
• Suggests that Google shares tracking data across their services
![Page 111: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/111.jpg)
Who is Cookie Matching?
Participant 1 Participant 2 Chains Ads Heuristics
criteo googlesyndication 9090 1887 P
criteo doubleclick 3610 1144 E, P DC, P
criteo adnxs 3263 1066 E, P
criteo rubiconproject 1586 749 E, P
criteo servedbyopenx 707 460 P
doubleclick steelhousemedia 362 27 P E, P
mathtag mediaforge 360 124 E, P
netmng scene7 267 119 E ?
googlesyndication adsrvr 107 29 P
rubiconproject steelhousemedia 86 30 E
googlesyndication steelhousemedia 47 22 ?
adtechus adacado 36 18 ?
atwola adacado 32 6 ?
adroll adnxs 31 8 ? 27
Heuristics Key (used by prior work)
E – share exact cookies
P – special URL parameters
DC – DoubleClick URL parameters
? – Unknown sharing method
![Page 112: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/112.jpg)
Who is Cookie Matching?
Participant 1 Participant 2 Chains Ads Heuristics
criteo googlesyndication 9090 1887 P
criteo doubleclick 3610 1144 E, P DC, P
criteo adnxs 3263 1066 E, P
criteo rubiconproject 1586 749 E, P
criteo servedbyopenx 707 460 P
doubleclick steelhousemedia 362 27 P E, P
mathtag mediaforge 360 124 E, P
netmng scene7 267 119 E ?
googlesyndication adsrvr 107 29 P
rubiconproject steelhousemedia 86 30 E
googlesyndication steelhousemedia 47 22 ?
adtechus adacado 36 18 ?
atwola adacado 32 6 ?
adroll adnxs 31 8 ? 27
Heuristics Key (used by prior work)
E – share exact cookies
P – special URL parameters
DC – DoubleClick URL parameters
? – Unknown sharing method
![Page 113: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/113.jpg)
Who is Cookie Matching?
Participant 1 Participant 2 Chains Ads Heuristics
criteo googlesyndication 9090 1887 P
criteo doubleclick 3610 1144 E, P DC, P
criteo adnxs 3263 1066 E, P
criteo rubiconproject 1586 749 E, P
criteo servedbyopenx 707 460 P
doubleclick steelhousemedia 362 27 P E, P
mathtag mediaforge 360 124 E, P
netmng scene7 267 119 E ?
googlesyndication adsrvr 107 29 P
rubiconproject steelhousemedia 86 30 E
googlesyndication steelhousemedia 47 22 ?
adtechus adacado 36 18 ?
atwola adacado 32 6 ?
adroll adnxs 31 8 ? 27
Heuristics Key (used by prior work)
E – share exact cookies
P – special URL parameters
DC – DoubleClick URL parameters
? – Unknown sharing method
![Page 114: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/114.jpg)
Who is Cookie Matching?
Participant 1 Participant 2 Chains Ads Heuristics
criteo googlesyndication 9090 1887 P
criteo doubleclick 3610 1144 E, P DC, P
criteo adnxs 3263 1066 E, P
criteo rubiconproject 1586 749 E, P
criteo servedbyopenx 707 460 P
doubleclick steelhousemedia 362 27 P E, P
mathtag mediaforge 360 124 E, P
netmng scene7 267 119 E ?
googlesyndication adsrvr 107 29 P
rubiconproject steelhousemedia 86 30 E
googlesyndication steelhousemedia 47 22 ?
adtechus adacado 36 18 ?
atwola adacado 32 6 ?
adroll adnxs 31 8 ? 27
Heuristics Key (used by prior work)
E – share exact cookies
P – special URL parameters
DC – DoubleClick URL parameters
? – Unknown sharing method
![Page 115: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/115.jpg)
Who is Cookie Matching?
Participant 1 Participant 2 Chains Ads Heuristics
criteo googlesyndication 9090 1887 P
criteo doubleclick 3610 1144 E, P DC, P
criteo adnxs 3263 1066 E, P
criteo rubiconproject 1586 749 E, P
criteo servedbyopenx 707 460 P
doubleclick steelhousemedia 362 27 P E, P
mathtag mediaforge 360 124 E, P
netmng scene7 267 119 E ?
googlesyndication adsrvr 107 29 P
rubiconproject steelhousemedia 86 30 E
googlesyndication steelhousemedia 47 22 ?
adtechus adacado 36 18 ?
atwola adacado 32 6 ?
adroll adnxs 31 8 ? 27
Heuristics Key (used by prior work)
E – share exact cookies
P – special URL parameters
DC – DoubleClick URL parameters
? – Unknown sharing method
![Page 116: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/116.jpg)
Who is Cookie Matching?
Participant 1 Participant 2 Chains Ads Heuristics
criteo googlesyndication 9090 1887 P
criteo doubleclick 3610 1144 E, P DC, P
criteo adnxs 3263 1066 E, P
criteo rubiconproject 1586 749 E, P
criteo servedbyopenx 707 460 P
doubleclick steelhousemedia 362 27 P E, P
mathtag mediaforge 360 124 E, P
netmng scene7 267 119 E ?
googlesyndication adsrvr 107 29 P
rubiconproject steelhousemedia 86 30 E
googlesyndication steelhousemedia 47 22 ?
adtechus adacado 36 18 ?
atwola adacado 32 6 ?
adroll adnxs 31 8 ? 27
Heuristics Key (used by prior work)
E – share exact cookies
P – special URL parameters
DC – DoubleClick URL parameters
? – Unknown sharing method
![Page 117: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/117.jpg)
Who is Cookie Matching?
Participant 1 Participant 2 Chains Ads Heuristics
criteo googlesyndication 9090 1887 P
criteo doubleclick 3610 1144 E, P DC, P
criteo adnxs 3263 1066 E, P
criteo rubiconproject 1586 749 E, P
criteo servedbyopenx 707 460 P
doubleclick steelhousemedia 362 27 P E, P
mathtag mediaforge 360 124 E, P
netmng scene7 267 119 E ?
googlesyndication adsrvr 107 29 P
rubiconproject steelhousemedia 86 30 E
googlesyndication steelhousemedia 47 22 ?
adtechus adacado 36 18 ?
atwola adacado 32 6 ?
adroll adnxs 31 8 ? 27
Heuristics Key (used by prior work)
E – share exact cookies
P – special URL parameters
DC – DoubleClick URL parameters
? – Unknown sharing method
31% of cookie matching partners would be missed.
![Page 118: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/118.jpg)
Summary
We develop a novel methodology to detect information flows between ad exchanges
• Controlled methodology enables causal inference
• Defeats obfuscation attempts
• Detects client- and server-side flows
Dataset gives a better picture of ad ecosystem• Reveals which ad exchanges are linking information about users
• Allows us to reason about how information is being transferred
28
![Page 120: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/120.jpg)
Inclusion Chains
• Instrumented Chromium binary that records the provenance of page elements• Uses Information Flow Analysis techniques (IFA)
• Handles Flash, exec(), setTimeout(), cross-frame, inline scripts, etc.
30
![Page 121: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/121.jpg)
Inclusion Chains
• Instrumented Chromium binary that records the provenance of page elements• Uses Information Flow Analysis techniques (IFA)
• Handles Flash, exec(), setTimeout(), cross-frame, inline scripts, etc.
30
<html><body>
<script src=“b.com/adlib.js”></script><iframe src=“c.net/adbox.html”>
<html><script src=“code.js”></script><object data=“d.org/flash.swf”></object>
</html></iframe>
</body></html>
DOM: a.com/index.html
![Page 122: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/122.jpg)
Inclusion Chains
• Instrumented Chromium binary that records the provenance of page elements• Uses Information Flow Analysis techniques (IFA)
• Handles Flash, exec(), setTimeout(), cross-frame, inline scripts, etc.
30
<html><body>
<script src=“b.com/adlib.js”></script><iframe src=“c.net/adbox.html”>
<html><script src=“code.js”></script><object data=“d.org/flash.swf”></object>
</html></iframe>
</body></html>
DOM: a.com/index.html Inclusion Chain
a.com/index.html
b.com/adlib.js
c.net/adbox.html
c.net/code.js
d.org/flash.swf
![Page 123: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/123.jpg)
3) Indirect Matching
31
Shopper-side Publisher-side
Exam
ple
Ru
le
![Page 124: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/124.jpg)
[^a]
3) Indirect Matching
31
Shopper-side Publisher-side
Exam
ple
Ru
le ^shop e [^a]$ ^pub .* e a$
![Page 125: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/125.jpg)
[^a]
3) Indirect Matching
31
Shopper-side Publisher-side
Exam
ple
Ru
le ^shop e [^a]$
Only the exchange e appears on the shopper-side…
^pub .* e a$
![Page 126: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/126.jpg)
[^a]
3) Indirect Matching
31
Shopper-side Publisher-side
Exam
ple
Ru
le ^shop e [^a]$
Only the exchange e appears on the shopper-side…
^pub .* e a$
e must pass browsing history data to participants in the auction, thus no
cookie matching is necessary
![Page 127: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/127.jpg)
[^a]
3) Indirect Matching
31
Shopper-side Publisher-side
Exam
ple
Ru
le ^shop e [^a]$
Only the exchange e appears on the shopper-side…
^pub .* e a$
e must pass browsing history data to participants in the auction, thus no
cookie matching is necessary
We do not expect to find indirect matches in the data.
![Page 128: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/128.jpg)
References
Gunes Acar, Christian Eubank, Steven Englehardt, Marc Juarez, Arvind Narayanan, Claudia Diaz. “The web never forgets: Persistent tracking mechanisms in the wild.” CCS, 2014.
Muhammad Ahmad Bashir, Sajjad Arshad, William Robertson, Christo Wilson. “Tracing Information Flows Between Ad Exchanges Using Retargeted Ads.” Usenix Security, 2016.
Marjan Falahrastegar, Hamed Haddadi, Steve Uhlig, Richard Mortier. “Tracking personal identifiers across the web.” PAM, 2016.
Lukasz Olejnik, Tran Minh-Dung, Claude Castelluccia. “Selling off privacy at auction.” NDSS, 2014.
32
![Page 129: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/129.jpg)
Filtering Images
Filter Total Unique Images
All images from the crawlers 571,636
Use EasyList to identify advertisements 93,726
Remove ads that are shown to >1 persona 31,850
Use crowdsourcing to locate retargets 5,102
33
![Page 130: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/130.jpg)
Filtering Images
Filter Total Unique Images
All images from the crawlers 571,636
Use EasyList to identify advertisements 93,726
Remove ads that are shown to >1 persona 31,850
Use crowdsourcing to locate retargets 5,102
33
![Page 131: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/131.jpg)
Filtering Images
Filter Total Unique Images
All images from the crawlers 571,636
Use EasyList to identify advertisements 93,726
Remove ads that are shown to >1 persona 31,850
Use crowdsourcing to locate retargets 5,102
33
• Personas visited non-overlapping retailers• By definition, retargets should only be shown to a single persona
![Page 132: Tracing Information Flows Between Ad Exchanges Using ......•RTB brings more flexibility in the ad ecosystem. •Ad request managed by an Ad Exchange which holds an auction. •Advertisers](https://reader034.fdocuments.us/reader034/viewer/2022042417/5f3273644bdc524b7346466c/html5/thumbnails/132.jpg)
Filtering Images
Filter Total Unique Images
All images from the crawlers 571,636
Use EasyList to identify advertisements 93,726
Remove ads that are shown to >1 persona 31,850
Use crowdsourcing to locate retargets 5,102
33
• Personas visited non-overlapping retailers• By definition, retargets should only be shown to a single persona
• Spent $415 uploading 1,142 HITs to Amazon Mechanical Turk• Each HIT asked the worker to label 30 ad images
• 27 were unlabeled, 3 were known retargets (control images)
• All ads were labeled by 2 workers
• Any ad identified as targeted was also manually inspected by us