I have privacy concerns about Facebook, and resent the fact that it's such a silo, but in the main in succeeds where other technologies have failed.

It's useful for finding people - a directory. If I want to get in touch with someone - and I don't have their contact details I can probably find them on Facebook and fire them a message.

If email was just as easy, people would have probably taken to that. Which is a shame, because Email could have been that easy. Privacy used to be more of a concern, and spam drove people away from publishing their addresses in directories.

I've left (privacy and personal reasons.) I since have missed the community. It's encouraged me to pick up the phone more, which is a nice thing. You just can't have the same rich interaction with people when typing compared to talking. But you can have a greater audience. Perhaps you communicate to more people with less content over something like Facebook, compared to having richer relationships with fewer people. It might all balance out.

Ultimately time is a premium. I certainly don't think G+ is the answer - it's much of the same.