A startup from my area that I wasn't involved with basically did this tactic. They found a number of people interested in the product they wanted to build. They

A startup from my area that I wasn't involved with basically did this tactic. They found a number of people interested in the product they wanted to build. They requested that the interested parties sign up at about $10/mo to be the first customers, and then the startup started building their product. Once they came around to launch time, the customers had already played around with the 'beta' product and given feedback, and nearly all of them have retained their subscription at $10/mo, where as new customers have to pay significantly more. I think its a reasonable trade off to give a discount to them, especially when they helped work through some of the bugs of the early phase. They may not be the customers that will make them rich by throwing them money, but they certainly helped get the startup to the position they are now.