You've got to Circle people to get people to Circle you back. If you want to enter into conversations you've got to follow a few folks. (Hangouts on topics you care about are a great way to meet and Circle people.) And as you begin finding your tribe on G+ you can create your own Circle based on your topics. For example I have Circles on MUSIC, TECH, and PHILOSOPHY. Go find your tribe on G+ and then Circle, Hangout, and share with them.
The good news is that Google Plus is already an astonishing platform and social network. And with the next rev of Google Plus you will begin to see the promise of the personal social dashboard, courtesy of Amazon and Google. (if the two companies ever got together, we probably would have the equivalent of Big Brother. And since any of your anonymous data can be purchased from Google OR Amazon, well... Buckle up for the ride, the "next generation" of the information age is already here.