I thought facebook started with a similar idea in some American university. These things tend to only be successful when they out-grow the original idea.
Yup, I had it back when it was that way. You could only get it if you were in one of a dozen or two colleges (it started with just one...), had to register with your school e-mail in order to get an account and the apps were limited to pics and a profile and a class engine to post your schedule and find people also in that class.
then they did the 'you can invite someone if you're already in' thing, which turned to a 'invite anyone you want' thing and finally a free-for-all which in my opinion ruined the whole thing. You suddenly get all sorts of games filled with 13-yr-olds and the adds change from cool college funnies to stupid all-age-appropriate things and the stupid stocker feed and so on. You have to then be careful of what you post and what you reveal. You get idiots you don't know asking you to befriend them so they could have an advantage in some game or another.
I wish they did keep it just for college kids (excuse the rant)