"A startup begins with a vision: a vision of a new product or service, a vision of how the product will reach its customers, and a vision of why lots of people will buy that product. But most of what a startup’s founders initially believe about their market and potential customers are just educated guesses. To turn the vision into reality (and a profitable company), a startup must test those guesses, or hypotheses, and find out which are correct. So the general goal of Customer Discovery amounts to this: turning the founders’ initial hypotheses about their market and customers into facts. And since the facts live outside the building, the primary activity is to get in front of customers. Only after the founders have performed this step will they know whether they have a valid vision or just a hallucination." - Four Steps to the Epiphany