An adult perspective
There.com is billed as a site for teens, but there are plenty of adults who spend time in here. It's a large enough world, with enough different places waiting to be colonised, that adults who want to create a calm oasis in which to chill and caht can freely do so away from the teenage party areas.
For me it's a way to relax away from the pressures of real life, and I've made virtual friends with people from all round the world. Great.
Of course, escapism has other interesting sides. I can be whoever and (more-or-less) whatever I want in the There.com world. So I can have a wonderful waterside home with fields and mountains out the back; and the cost of renting the space and buying the goods is likely to feel modest to a middle-aged person.
On the other hand - I could pretend to be a teenager (which I'm definielt not) - and so the usual precautions about on-line safety that you'd apply to MSN or Bebe are still important.