Twitter has been my life's work in many senses. It started with a fascination with cities and how they work, and what's going on in them right now.

'Luck' is recognizing when the situation encourages build out and execution.

It's empowering to be asked to look at what's possible, not told how to do it.

Anything you're interested in the world whether it be Charlie rose or JetBlue or a public figure or your local coffee shop, they're on Twitter and broadcasting what is interesting to them.

Twitter has been my life's work in many senses. It started with a fascination with cities and how they work, and what's going on in them right now.

The interesting products out on the Internet today are not building new technologies. They're combining technologies. Instagram, for instance: Photos plus geolocation plus filters. Foursquare: restaurant reviews plus check-ins plus geo.

Twitter was around communication and visualizing what was happening in the world in real-time. Square was allowing everyone to accept the form of payment people have in their pocket today, which is a credit card.