I know what you mean, it felt the same way when I started. I was sitting there, wondering how to get more of my Facebook people over to G+ since it felt so empty.
Then I started following William Shatner, then Guy Kawasaki, Alyssa Milano, Tren Reznor, Wil Wheaton, Michelle Marie. It's led to having WAY more people I'm following and engaging with. It definitely had a ramp up time, but I found that engaging in posts was a great way to find like-minded people, and since I can follow them without them having to agree to be "friends", I began to experience an exponential growth in stream volumes.
Some of those people I began as simply following, have now added me as they see my comments and realize I'm someone they like. My Facebook feed is far more stagnant and less interesting than G+. I only go to Facebook these days to see what's going on with those folks who are only over there. As someone else said, I don't hope or want G+ to replace Facebook, competition is good...beside, thus far my personal experience is that G+ people are of higher quality than Facebook. Of course, volume and the fact that average Joe won't be on G+, at least for now and the near future, affects this.
In the end, Facebook was pretty dead for me when I started, as I've never maintained a huge network of friends..it took months until I didn't feel like I was in my own chat room. It was a similar experience for me with Google+, just didn't take as long once I stopped looking at it like Facebook.