Well, Facebook is what you make it. For us, it's a great way to communicate w/ family and friends, share photos and videos, share news article and such w/ friends w/ whom we have common interest, etc.
Some may argue that e-mails would work, but I appreciate being able to interact instantly w/ many friends. We still send out e-mails anyway, FB is just a way to share the little things that wouldn't necessarily make it into a long mail. With family and friends in Canada, it helps feeling closer, because we can share those little things on an ongoing basis.
Plus, phone numbers and address change all the time - for us and many friends - but we stay in touch via FB.
And after winning a DBX compressor, a Lexicon reverb and a Steinberg remote control in the last 2 weeks, I can hardly complain about FB. ;)