So I've only had this for like an hour and I think I have it figured out. It's basically the same thing as facebook, but with less people, and lack of people is kind of a problem for a social network.
The major difference is facebook says 'You have your list of friends, you can also share with groups of people, but nobody does that.' Google+ markets it as, 'You have groups of friends, or you can share with everyone, but nobody does that.'