That's certainly true, but that's not why it will last. Most of the sites Justin listed are too specialized to be simple enough for most users. Facebook allows people to do a lot with one login, having to remember only one URL. And so far, not even the mighty google has been able to come up with anything to challenge it. And even if someone does come up with something far better, it will take a vast migration of users to make it worth changing over for, probably, the vast majority of facebook users. It's a bit of a catch 22, because facebook itself is nothing special, it's the fact that everyone is on it that makes it worth using. Google+ might have been the best thing ever, but I never found out because after a couple of days of tinkering with it, I realized that nobody I knew was on there and not on facebook, so why bother going elsewhere for some (but not all) of the same people I was interacting with already?