Time Spent on Google, Yahoo!, MySpace, and other sites

Compete.com released data a while back estimating the amount of time spent online across 20 sites. Don Dodge gave an informed take on this data here. One of the points that missing in all of the discussion is the practical utility of the information presented. That is not to say that it's not interesting to ponder on a macro scale how much time a person chosen at random is spending on MySpace, Yahoo, and other sites. My point is that the value of information like this presented in this way is limited. The basic reason is that people are different and the contexts in which they use a MySpace verses a Yahoo! verses a Google are different also. For example, my mother has never and will never spend a second on MySpace eventhough she's online a couple of hours every day. So, in addition to providing interesting data what I'd love to see is data that is useful as well. For starters, how about slicing the time spent by a few basic demographic dimensions (age and gender)? Then we'd have something to talk about...