The long lost formula for start-up success.

The first phase of the process is customer discovery, which is identifying who the people are with the problem. This is harder than it sounds as they must not only have the problem, they must realize they have a problem and be willing to invest time and money in a solution to that problem. These are your early adopters. They are willing to overlook shortcomings in your product and believe that you will make it better with time.
(Link: The long lost formula for start-up success.)