In my experience, Google+ is a great place to find passionate communities of small niches. Tabletop role-playing games, for example, have thoroughly adopted G+.

In my experience, Google+ is a great place to find passionate communities of small niches. Tabletop role-playing games, for example, have thoroughly adopted G+. Google+ falls down for mainstream users, though, which is where the "no one here" perception comes from. If memory serves, Google Wave was the same way: great for the people who used it, but the value wasn't perceived by the majority.