"A really good friendship would have found a way to stay alive over 10 years with or without Facebook." That's true, and I certainly have friends that I intend

"A really good friendship would have found a way to stay alive over 10 years with or without Facebook." That's true, and I certainly have friends that I intend to stay in touch with for many years to come, Facebook or no. Relationships fall into concentric circles though; there's acquaintances on the outside that only care about slightly, and there's lifelong friends near the centre. Somewhere in between are people that you would certainly talk to if you ever ran into them at random, but wouldn't make much of an effort to stay in touch otherwise. Facebook is ideal for these kind of relationships, because the semi-public nature of wall posts keeps things casual (letters and emails feel very intimate, and it can be strange sending a long "hey, what's up?" message to someone you don't know that well). There's also the fact that you can see their recent activities and photographs, giving you an easy conversational opener ("I saw you visited x/did y/know z, how was it?"). I think it was quite carefully designed to afford such interaction styles.