One of the things we have to decide upon as humans is the impact of things that we do on our daily lives. That is, what benefit do we derive from things that others think is necessary? If you had to make a decision on something based on the benefit it gives you, what would you decide on things like Facebook, Twitter and the now-antiquated MySpace? I'd guess that the benefit is nearly zero, and that you are only on those so-called social networking sites because other people you know are on them. But, when is the last time you did something merely because everyone else does it?
If Johnny Finnegan jumped off the Brooklyn Bridge, would you jump off, too?
That's the question that our parents would ask us whenever we told them that we were doing something because everyone else did it. Somehow, the Facebook and Twitter thing became popular - probably because our friends started doing it and we felt like we should do it too, or else we would be left behind. What we failed to realize is that our friends already knew where we were, and they didn't need an Internet site to know which high school we graduated from or whether we wanted to play Mafia Wars or Farmville - which most of us do not.
So, we became sheep and jumped on. We formed our little page with photos of us with our pets or children (or both) and became part of the "community." It's like that Jim Jones thing, only the Kool Aid doesn't have any flavor.
Mostly, we don't want people to know too much about us. That's what happens when our identity is stolen - they know too much about us. So, why do we feed into it with Internet pages that have our names, places of birth and other personal information? I think it's because we long to be important, but lack the necessary tools to make it happen, so we self-promote on a made-up web page.
I'm not sure what it's supposed to be, other than some sort of self-promotion or "look at me" thing. Maybe that's enough, or maybe it isn't.