The one thing with stress is, you've got to keep your focus on what you can do, not what happened to you.

The most important thing you can learn as CEO- one of the hardest things to do is, you have to discipline yourself to see your company... through the eyes of the people that you're working through. Through the eyes of the employees, through the eyes of your partners... through the eyes of the people who you're not talking to and who are not in the room.

Every time you make the hard, correct decision you become a bit more courageous, and every time you make the easy, wrong decision you become a bit more cowardly. If you are CEO, these choices will lead to a courageous or cowardly company.

Most large mistakes in organizational design come from putting the individual ambitions of the people at the top of the organization ahead of the communication paths for the people at the bottom of the organization.

There are no silver bullets.

There is no silver bullet. There are always options and the options have consequences.

Groupon looked like a very high valuation, but any investment in a great company at any stage is almost always a good investment.