People are narcissistic by design. Social Networks were created to harness that narcissism to make money. I argue that there are a lot of other 'social networks

People are narcissistic by design. Social Networks were created to harness that narcissism to make money. I argue that there are a lot of other 'social networks' on the internet in a technical sense. You had profiles and added friends and then sent things to them/chatted with them on AIM, LiveJournal, any of a number of message boards, blogs/comments, etc. The deciding factor between what came before and facebook and twitter is the ability to broadcast to the entire social network at once, so all of the world can see your brilliance! Feeding into that narcissism is the killer feature of modern social networks.