In my ATG Performance Tuning post I mentioned that how a user perceives the site performance impacts their behavior on the site, and that a fast site leads to more purchases/traffic/etc…

Here are some numbers to back that up:

  • Amazon found that a 100ms increase in page response time led to a 1% DROP in sales, or conversely improving a page response time by 100ms will increase sales 1%. I suspect that this effect continues beyond the 100ms mark, but probably tapers off at some point.
  • Google found that an 500ms increase in page response time led to a 20% drop in traffic and revenue. This is despite the 3X increase in search results delivered (30 results instead of the default 10) to the test group.
  • Google also found that a 30% reduction in page size resulted in 30% more traffic/usage due to faster loading and rendering.

Given the relatively low cost/time in performance tuning your application, the resultant gain of 1%-20%+ in revenue makes it a smart move.

“As Google gets faster, people search more, and as it gets slower, people search less”
— Marissa Mayer, Google vice president of search products and user experience

This is also true for your website, just replace search with “buy”, “read”, etc…

In fact, I’ll lay down a wager: If you improve the page rendering time of the most visited pages of your ATG site by over 10% or 100ms (which ever is greater), and you don’t see any improvement in your goal conversion (purchases, sign-ups, whatever your measured goal is) I will give you an iPhone.

My up-coming posts on ATG Performance Tuning will make it easy to improve the page performance much more than that. I’d expect most ATG sites can cut the user experience of page loading and rendering time by 50%, or more, based on the advice I will be posting here.

So check back often!