The two examples you have aren't really comparable. In the case of Google Wave, this was an experimental new way of communicating. I remember it being cool and

The two examples you have aren't really comparable. In the case of Google Wave, this was an experimental new way of communicating. I remember it being cool and exciting at the time, but I definitely didn't get the impression it was a commercial product. And afterwards they ended up open-sourcing the whole thing as an Apache project. Google Buzz was a little less experimental, but as another poster mentioned, it was a free consumer product and second it ended up being superseded by Google+.