Here's the new video in the series by commoncraft explaining social networking. Ofcourse I'm eagerly waiting for the social bookmarking one after our own attempt.. But you watch it differently after you tried to produce one!
As for social networking site, I've become a member of linkln and facebook, but I don't invest in it and it doesn't work for me. For my case, the video doesn't help in explaining the principle, or do I miss the clue because I'm not looking for a new love neither for a new job?