Website performance

Why invest in improving page loading speed

Bing.com/Live.com

Slower site = revenue drop

1 sec = 2.8%2 sec = 4.3%

Gets worse with time

After-effect

Google

Yahoo!

• 0.4 seconds slower = 5-9% drop in full-page traffic

Slower pages get less traffic

AOL

Improving from 6 sec down to 1.2 seconds

Shopzilla

Shopzilla

• Every little bit counts

• Cookie-free components: +0.5% more revenue

Netflix

• 43% drop in outbound traffic after enabling compression

Faster site means:

• More repeat visits• More page views per visit• Better conversions• More revenue• Increased user satisfaction• Hardware and bandwidth savings• More (sponsored) search engine traffic

Where do we focus?

Example: Ashton Kutcher’s Twitter

First view (empty cache)

10% 90%

Repeat visit (full cache)

38% 62%

Where to focus?

• Focus on the front-end• That’s where the time goes• Easier to improve

Thank you!

Credits/URLs• Google, Bing: http://en.oreilly.com/velocity2009/public/schedule/detail/

8523 • Shopzilla: http://en.oreilly.com/velocity2009/public/schedule/detail/7709• Netflix: http://en.oreilly.com/velocity2008/public/schedule/detail/3632• AOL: http://en.oreilly.com/velocity2009/public/schedule/detail/7579 • Yahoo!: http://www.slideshare.net/stoyan/yslow-20-presentation • Bing graphic: http://www.watchingwebsites.com/archives/proof-that-

speeding-up-websites-improves-online-business • Steve Souders: http://stevesouders.com• Stoyan Stefanov: http://phpied.com • Sponsored search and speed:

http://adwords.google.com/support/aw/bin/answer.py?hl=en&answer=87144