Optimizing for speed
Interesting point from Scott Porad on optimizing page load times. Hint: it’s not about the images; it’s about the http calls.
In other words, the frequency of visits as a factor in reducing empty cache visits is counteracted by the frequency that a site’s content is updated. Of course, this makes sense because unless a site updates it’s content frequently users don’t have a reason to return frequently.
The bottom line: reducing HTTP requests continues to be most important for improving site performance.
Scott found a research report that notes 20% of users have no cache, making local caching a moot point. (I know this first-hand; on my creaky old Windows box at Clarins, I set my own cache to zero, because it minimized the internal RAM and hard drive needs and sped up page rendering.) More important, especially in this era of Ajax, is to minimize server requests, which create the bottlenecks.
Considering Google’s new inclusion of site speed in PageRank this is going to be a key performance metric in 2010, and one to monitor regularly.