The frequent appearance of tween oriented content on Twitter's trending topics list had me wondering what was going on: why, if few people under 24 were allegedly using Twitter, were Miley Cyrus and the Jonas Brothers all over the twitter stream. Was it spam? Or something more insidious?
The presentation above explains it all.
UPDATE: Check out the comments on Slideshare from noted anthropologist Danah Boyd, of the famed study pointing out class differences in MySpace and Facebook users (long before said differences became glaringly obvious). Great stuff and flattered to have her insight.