Well, personally, I use facebook for two main reasons: Easy contact with friends I don't live close to (which is a lot, since lots of my friends live in different cities/countries), and easy organisation with groups I'm involved with (lots of societies and university related groups I'm involved in use facebook as their main communication method, so if we want to arrange a meeting, share some work/files/papers, or share information about events, they use FB).
I think if you put moral problems to one side, lots of the social downsides of FB can be avoided by unfriending people you don't like, or who annoy you.
Be grateful you're using european sizes, mines 7.