Do Small Changes in Performance Really Matter?

The Velocity 2009 "Web Performance and Operations" conference took place in San Jose this year on June 22.   Attending the conference were developers, engineers, and managers from companies of all sizes, focusing on web performance.   So, do even the smallest changes in performance matter?  Lets have a look at what some of the big players had to say.

• Microsoft (Bing) found that 2 additional seconds in response time reduced the number of searches per user by 1.8% and decreased revenue per user by 4.3%.
  
  
• Google found that a 400 millisecond delay resulted in 0.59% fewer searches per user and that even after the delay was removed, these users still had 0.21% fewer searches, indicating that a slower user experience affects long term behavior.
  
  
• Shopzilla conducted a year-long performance redesign reducing response times by 5 seconds (from ~7 seconds to ~2 seconds) resulting in a 25% increase in page views, a 7-12% increase in revenue, and a 50% reduction in hardware.
  
  

Source:  Steve Souders @Velocity Conference 2009
http://radar.oreilly.com/2009/07/velocity-making-your-site-fast.html