I finally got around to reading the second article on browser performance optimisation on the YUI blog. While the techniques aren’t new to me (I work on the Yahoo! front pages for Europe remember), some of the data was.
“40-60% of Yahoo!’s users have an empty cache experience and ~20% of all page views are done with an empty cache”
This is incredible! If ever there was a good reason to optimise your code this is it. I would have expected something more like 75% to be using full cache. I do wonder if the front page is the best example, however, and if other deeper Yahoo! sites would have a higher rate of caching among their users. This is because the Yahoo! front page is often the first destination for users, and there are known IE issues with start pages.
(Via Yahoo! User Interface Blog.)