Customers don't care how much time something takes to build. They care only if it serves their needs.

In a startup, both the problem and solution are unknown.

What differentiates the success stories from the failures is that the successful entrepreneurs had the foresight, the ability, and the tools to discover which parts of their plans were working brilliantly and which were misguided, and adapt their strategies accordingly.

Science and vision are not opposites or even at odds. They need each other. I sometimes hear other startup folks say something along the lines of: 'If entrepreneurship was a science, then anyone could do it.' I'd like to point out that even science is a science, and still very few people can do it, let alone do it well.

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

Except in very narrow cases, where there's breakthrough science that needs patent production, worrying about competitors is a waste of time. If you can't out iterate someone who is trying to copy you, you're toast anyway.

The minimum viable product is that version of a new product which allows a team to collect the maximum amount of validated learning about customers with the least effort.