Vanity metrics are the numbers you want to publish on TechCrunch to make your competitors feel bad.

Sustainable growth is characterized by one simple rule: New customers come from the actions of past customers.

This is one of the most important lessons of the scientific method: if you cannot fail, you cannot learn.

If the plan is to see what happens, a team is guaranteed to succeed - at seeing what happens - but won't necessarily gain validated learning - If you cannot fail, you cannot learn.

What if we found ourselves building something that nobody wanted? In that case what did it matter if we did it on time and on budget?

Reading is good, action is better.

At IMVU, the cost of customer acquisition through our five-dollar-a-day AdWords campaign was less than twenty-five cents. Our revenue from those same customers was more than a dollar.