In my first start-up, I had an initial advertising budget of $5 per day total. That would buy us 100 clicks per day. At $5 per day, marketing people scoffed and said that is too small to matter. But if you think about it, to an engineer, 100 real humans everyday giving your product a try means you can really start improving.

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.

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?

Here in Silicon Valley, I have taken part in hundreds of conversations trying to convince people to dive in and become entrepreneurs. All too often, innovators with good, safe, jobs are unwilling to put their family's access to health care at risk by walking away from company-backed medical insurance.

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

All innovation begins with vision. It’s what happens next that is critical.

Learning is the essential unit of progress for startups.