I had a cohort of friends from grad school that used Buzz like crazy. We tried Google+, but it just wasn't as useful. This would have been 2008-2010.

We also really wanted to use Google Wave, but couldn't get enough invitations to go around. It was like nobody at Google figured out that the only reason invitations worked for Gmail was because Gmail was interoperable with email. Wave didn't interoperate with anything. Either your friends were on it and you could use it, or they weren't and you couldn't. 3-4 invitations after a couple months just wasn't enough of a social effect to make it useful like it had been for Gmail.