Excerpt from an extensive interview
"I was pretty tense when Google shut down Wave. I can't say they were really wrong to do so, but it was very hard. I knew it was time to move on.
I was disappointed as it was my creation and it failed. It was ambitious, and you should be ambitious, but the mistake was to rely a lot on the resources we had. We grew the team very quickly and based the idea on the resources we had and it's not clear that it worked.
Sergey (Brin, co-founder of Google) always said 'scarcity brings clarity' and I wish I'd understood that a bit better. I still believe email is outmoded and we could do something better. But it was painful."