This is playing out very similar to how Android did. At first it was considered unnecessary and a flop, and even ridiculed. Yet it continued to grow even when Iphone was the only name in town. Then over time you started to see more Android phones and the media began at least accepting that it was here to stay even though few believed it was a real competitor to the Iphone. Then it hit critical mass after about 2 years of existence. G+ has a ways to go before it hits critical mass, but the similarities of its growth and Android's growth just a few years back are striking.