[peoplewindow]

Linux became popular because it was free as in beer, because it was essentially a clone of pre-existing systems that lots of programmers happened to like (the commercial UNIXes) and because those competing systems were fairly stagnant.

So far open source communities haven't really tried to clone Facebook to the level of detail required to make people feel at home, and you're already competing against 'free'. So that avenue isn't available either.

I suspect it isn't possible to compete with Facebook because for most people it isn't broken.