experiential learning, how long and who stays in sl, why do they use sl?

I wonder whats the sl gamer profile, how old are the sl players?
20 somethings like to go out and meet real people. So who are the people who must meet in sl? How old are they in general? And why are they in sl and not in rl?

If it is not for a short passage of time, not for some realistic practical purpose, for example making creative use of the capacity of sl in building, in chat etc.

Those who only use it for social purposes which never leaves sl, what does this mean?

If someone stays online chatting only all the time, what does this mean?

:)