I really don't think g+ offers enough to make people switch. I remember the switch from myspace to Facebook was a breath of fresh air. Myspace was horrible, which made the change a very easy decision. Sure facebook has some problems but enough to make the average person transfer everything to a new networking site? Most of my friends can care less about g+ because Facebook works just fine for them.
tell me what the difference between facebook and myspace was ? because if you remember when faebook FIRST came out, it was under developed, much more then G+