The last fundamental principle that applies throughout the Nail It Then Scale It process is to conduct rapid, inexpensive, simple experiments in the field to test your guesses and hypotheses rather than building products. This principle depends on the recognition that whatever you believe about your product, customers, or market is a hypothesis that needs to be proven. Few entrepreneurs actually recognize this, and so, feeling eager to get to market with something to sell, they start building the product. The danger is that when you build a complete product based on a guess about what customers want, even your best guess, you are bound to be wrong in ways you couldn't imagine.
Of course a lucky few do get it almost right on the first try. However, probabilistically these cases are very low. Hence the high mortality rate for new ventures. Unfortunately, entrepreneurial myths are perpetuated by the few entrepreneurs who get lucky and guess right. In contrast, if you talk to a group of successful, thoughtful entrepreneurs, they will tell you how dramatically their product changed from beginning to end.
(See Nail It Then Scale It, pgs. 56-62)