The mistake isn't releasing something bad. The mistake is to launch it and get PR people involved. You don't want people to start amping up expectations for an early version of your product. The best entrepreneurship happens in low-stakes environments where no one is paying attention, like Mark Zuckerberg's dorm room at Harvard.

Entrepreneurship is not really building a product, it's not having an idea, it's not being in the right place at the right time. It's fundamentally company building.

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.

Progress in manufacturing is measured by the production of high quality goods. The unit of progress for Lean Startups is validated learning-a rigorous method for demonstrating progress when one is embedded in the soil of extreme uncertainty.

Innovation is a bottoms-up, decentralized, and unpredictable thing, but that doesn’t mean it cannot be managed.

Start-up success is not a consequence of good genes or being in the right place at the right time. Success can be engineered by following the right process, which means it can be learned, which means it can be taught.

Because startups often accidentally build something nobody wants, it doesn’t matter much if they do it on time and on budget. The goal of a startup is to figure out the right thing to build - the thing customers want and will pay for - as quickly as possible.