Facebook is unique in that you can communicate with your freinds on a level that you are otherwise unlikely to in real life. Unlike myspace, I find facebook more adaptable.
I am less of a status updates person and I switch off my chat box option too. When I want to talk I talk to people via inbox and I love that aspect so much. It gives me a chance to really talk to people. Of course only when I feel it is wanted and its so liberating when you can truly start expressing yourself without needing to tone down or go into superficial stuff like how have you been, or how was your day and all that mundane stuff that is asked often. I love to talk in an abstract way and when I can do that with others facebook rocks big time.
And I am able to reconnect with as many friends as I like. Even my extended family I had no idea I had until recently so that is great too. And yes it is to leave the lines of communication open with many of my past friends and current.
And plus its an excellent way to create events to go out and do things with your friends, you know your friends that you spend time with in real life. And to invite others to join you in activity that you otherwise might not have done so.
And then you can create or join interest groups that are almost like forums where you talk about your interest too, that is rather cool when there are enough people who interact with you.
And then there are apps, all sorts of apps. You get the good, the entertainment, the spam and the pointless, depends which app you find that suits your needs and wants.
I saw a cool "solar system" of the big service providers on the internet and there was like Google was a Saturn like Sun and Facebook was the biggest sattellite after that, Amazon a close third and rival with ebay for size.
When I joined Facebook during my last year of college (when it was exclusive to college students), it was a great way to get to know people with similar interests, especially since I didn't live on campus, take many classes away from my dept., etc. Rather than reconnecting with people from my past, I was connecting with people from my present.
But post-college, I wasn't really in a position to be meeting new people (ie. being a hermit), so it became useless until they opened membership to everybody. That's when kids from high school started friending me. And I didn't particularly like high school as an experience or the version(s) of myself during those years.
It's kind of depressing now. I feel more left out using it, but I also wouldn't have a social life if I didn't use it. Damned if I do, damned if I don't.