Just not interested in Google+. It was enough of a struggle to coax me onto Twitter and Facebook. I don't hear non-techies talking about Google+--it's all dedicated bloggers and people in the "Twittersphere" (ugh).
Not to mention that I heard all sorts of revolutionary praise for Wave when it was released.
The thing that is hooking me in Google+ is that it's just my google account. I don't really have to think about going there unlike the other services. And what killed Facebook for me was the UI. When it became too cluttered I just got tired of it. I hate battling with a website. Google+ UI seems more polished already that what Facebook has/had(I haven't used it seriously in the last 2 years. I sporadically log in and feel like I'm going through my email thrash. )
Did non-techies hear about Facebook in the first 2 years of its existence? Techies know about it first because they are up to date to such things. Once people on radio and TV start talking about it, they'll know about it, too. That's how the mainstream works, otherwise it wouldn't be called mainstream anymore.
> Did non-techies hear about Facebook in the first 2 years of its existence?
Every single human attending Harvard in 2005 heard of thefacebook, and almost all of them were active users. This pattern continued as it expanded to other colleges, and eventually high schools. Facebook had a steady, population-representative mix of non-technical users from birth; it was never techies'-little-secret in the way that Twitter, Foursquare, and Quora were.
Warning: I work at Facebook now, but did not back then. This is just my second-hand understanding.
Not to mention that I heard all sorts of revolutionary praise for Wave when it was released.