You have to think for an email. What's the subject? What's it about? It takes two seconds to think about that. So you have to think, Is this a work thing or a social thing? Which? Then you get into a situation that you don't want to be in, because then people are thinking about it too much.

We hired a CSR person at Twitter, years before we hired our first sales person, to make sure we had a culture and impact of doing good.

When you hand good people possibility, they do great things.

When a plane lands in the Hudson and there's a Twitter user on the ferry taking a picture of it, Boom. That's it. The water is still splashing. Here's the photo of the thing.

There's a lot of social input when you put these things out there. People's ideas cross with other people's thoughts.

With Twitter, it's as easy to unfollow as it is to follow.

Twitter provides a great amount of timely information, but we still need those people to fill out the rest of the story and the context.