Most of my friends live too far away for me to see them in person. I'm not too keen on the idea of long-distance calls to ask my friends how it's going. Facebook is the most convenient way to contact people. If you suddenly realize you need to contact someone, but you don't have their contact info, chances are, they have facebook. All you need is their name. It's also the best way to have long-distance conversations with multiple people where anyone can join in.