I just signed up this week. I figured, since I'm about to move and change my name, I'd better leave a breadcrumb trail for people to find. There was exactly one person each from my high school and college graduating classes.
Other than checking that, I haven't a clue what to do with it. I'm just hoping to seed enough online information that a Google search will turn me up. I've got a TON of online presence, but all anonymous. Sadly, I share a first and last name with a historical person's mom, so my Google trail will be muddied in any event.