The strongest thing you can cultivate as an entrepreneur is to not rely on luck but cultivating an ability to recognize fortunate situations when they are occurring.

Build what you want to see in the world.

The greatest lesson that I learned in all of this is that you have to start. Start now, start here, and start small. Keep it Simple.

Make every detail perfect and limit the number of details to perfect.

We get to design what we want to see in the world rather than doing what other people think should be done.

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.

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.