I think Gmail was a special case: a highly anticipated product that was better than anything else out there, it had a killer feature that was unheard of (1GB of

I think Gmail was a special case: a highly anticipated product that was better than anything else out there, it had a killer feature that was unheard of (1GB of storage and growing!), and you could immediately use it as your main email. It didn't work out so well when they tried to reproduce that success by making Google Buzz invite-only. My feed consisted of a few people posting "buzz!" and then never posting again. Google+ was similar.