Online social networks: Everywhere and nowhere

So it is entirely conceivable that social networking, like web-mail, will never make oodles of money. That, however, in no way detracts from its enormous utility. Social networking has made explicit the connections between people, so that a thriving ecosystem of small programs can exploit this ⌠social graph■ to enable friends to interact via games, greetings, video clips and so on.

http://www.economist.com/displaystory.cfm?story_id=10880936