MySpace: Hot or Not?
readwriteweb.com
readwriteweb.com
The mistake is assuming that people spend a lot of time admiring the pages. The homepages are absorbed quickly, at which point pople move on to listening to music, looking at pictures, commenting/messaging, or looking for more people. You can waste hours browsing through profiles, it's a lot like wikipedia clicking. It's also a lot like people-watching on a busy street.
I log into facebook if I get a message from someone, or meet someone new irl and want to add them. I putter around for a little while, maybe play with a couple of gimmicky mashups for a few minutes. Then I log out and don't check it again for weeks.