Just saw a nice article by Carl Mangold in which he proposes to drop the term social network as research shows that the main reasons for users to generate content are fame and fun. Furthermore there are only few of the participants in such networks that actually produce content themselves (sorry, the post is in Dutch, but the accompanying graphics are in English). So where is the social aspect then.
I agree with Carl on his analysis but I would add to it that the effects described are probably influenced by culture. I think that American users, more than European users, generate user content for publishing reasons (fame and fun). I think that European users on Facebook, Myspace, and also European portals with similar functionality will in general use it more often to get in touch with friends they know in the physical world as well (so more sharing going on here). Nevertheless, publishing for fame is an important factor that drives a lot of these portals.
I think that for “real” friends sharing SMS, IM and e-mail are more popular than services like Facebook or MySpace. Why? Well, my guess would be that sharing using SMS, IM or e-mail is just quicker and easier to do. Simple interfaces, direct sharing possibilities and in most cases a direct response from the friend you are sharing with. Sharing is more personal, it isn’t a public interaction the way publishing is. It is an important social interaction though. The service that will support sharing between friends best might just be able to attack the more conventional methods used. What do you think?