Ah — just as I thought. BBC News reports that:

Fans of MySpace and Facebook are divided by much more than which music they like, suggests a study.

A six-month research project has revealed a sharp division along class lines among the American teenagers flocking to the social network sites.

The research suggests those using Facebook come from wealthier homes and are more likely to attend college.

By contrast, MySpace users tend to get a job after finishing high school rather than continue their education…