Don't count Google out yet. Just because it hasn't become hugely successful in it's first year doesn't mean it won't. How many users did Facebook have in 2005? Twitter in 2007? Google has put enormous resources behind Google+, and they don't show any sign of backing down. They're taking dozens of separate services that they provide and integrating them through Google+. In 5 years, that's going to be a very compelling platform.