Scratch's community is very different from other kinds of social media: it's strictly regulated by the MIT folks, so content is always friendly, welcoming, and age-appropriate. As a result of this, people tend to be encouraged to work together: you would be surprised what 10-year-old kids have produced together. A large part of Scratch culture is "collaborations" and "companies" which can produce large pieces of software with really incredible co-operation--better than a lot of adults I deal with :-)

I guess Scratch as a social network tries very hard to de-emphasize numbers: there isn't a "karma" and "likes" don't bring you much (interestingly, the number of "remixes", or derivative works of your project, is emphasized much more).

I can point you to some of the LLK's published papers on this if you're interested.

(Source: Scratch community member for >5 years.)