Startup CEOs should not play the odds. When you are building a company, you must believe there is an answer and you cannot pay attention to your odds of finding it. You just have to find it. It matters not whether your chances are nine in ten or one in a thousand; your task is the same.

When you're making a critical decision, you have to understand how it's going to be interpreted from all points of view. Not just your point of view, not just the person you're talking to, but the people that aren't in the room. Everybody else.

As a company grows, communication becomes its biggest challenge.

The key to high-quality communication is trust, and its hard to trust somebody that you dont know.

The person they're working with, is going to be the person they'll know more. So if that person leaves, they're going to go - well, should have I left too? What did they get and how does that compare to my deal.

It's pretty clear that [customers] know what their budgets are now, and what they want to spend it on.

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