Ries describes five core principles: 1. Entrepreneurs are everywhere—anyone creating new products or services in the face of extreme uncertainty. 2. Entrepreneurship is management—one can use processes to navigate uncertainty, and so these processes must be managed. 3. Validated learning—startups exist to learn how to build a sustainable business.

scaling a startup is more expensive. That’s because as more and more of these startups exist, they start to saturate the best online distribution

4. Wading in the Value Stream—We explain how to posit the value you are creating. 5. Diving In—We introduce various methods of customer interaction to learn. 6. Viability Experiments—We talk about various methods of running experiments to de-risk your market.

Don’t follow your passions; follow your effort. It will lead you to your passions and to success.

lean manufacturing is about optimizing efficiency in all value-added activities and minimizing or eliminating all non-value-added activities, where value added means providing value to customers.

In 2011, famed Internet-entrepreneur-turned-venture-capitalist Marc Andreessen described how technology companies are disrupting entire industries. He called this phenomenon “Software eating the world.”

optimization that adversely affects value being provided is not lean.

First, be a learning organization.

A lean startup is not ready to scale until the product itself is the best marketing tool.