The single most important top-level trend is the shift to mobile.

You can't get married to any one particular plan. That is the biggest lesson I learned at PayPal.

Media is very different from financial services. People are very fickle and very vocal. They believe that things should be one way and not the other. It's still very rewarding to build products for huge audiences. It feels like you're making an impact.

Right now, nearly all the apps on Facebook take a week to build. No more.

Facebook is so ubiquitous now that it's like another manifestation of the web itself.

Ignore your mistakes. The number one thing to worry about is -Am I doing what I'm good at?

Having a highly homogeneous background, education, values, preferences, etc, in the very early team is better than not - cuts down on time-wasting arguments.