Speaking for the U.S, It’s showing a similar pattern so far. Facebook once seemed very professional, almost like an elite gathering. It looked much cleaner, and it was intimate, since you had to Friend people in order to see much of anything. While MySpace had deteriorated into full-blown mess of teenage hormones and poor layout judgement. At the time, I think there was a higher bar in order to have a Facebook profile. You had to be a student or a grad or something. I remember not being eligible for quite some time. Facebook felt like a ritzy private school while MySpace was the raucous public school. I got onto Google+ pretty early thanks to an invite from a German acquaintance of mine. Like my first impression of Facebook, it felt, as you can predict; “clean, professional, intimate”... But fairly empty. The userbase is of equal importance to the usability. Google+ has the usability part down to perfection, but as for the userbase; only time will tell (and if Facebook keeps making unwise decisions, there’s no reason they won’t go the way of MySpace — who completely dropped the wrench as far as usability went, which is what scared everyone over to Facebook.) And usability alone can’t save it, obviously, as I’ve used many social networks that I felt were inherently “better” than MySpace that never managed to emerge victorious. Internationally, I’m not sure what could happen. Facebook is the first social network that seemed to be accepted globally. In the MySpace era you had to maintain a Friendster, Hi5, Multiply, Mixi, et al. to keep in touch with global friends that just couldn’t dig MySpace. Surprisingly, all of those friends have adopted Facebook, so for the past few years it’s been the only basic social network worth using. As for myself, I will continue using both, until one or the other inevitably dies down.