Don Haderle suggests you pull the plug when you cannot find one happy person. We were in development, but in reality we were R&D building prototypes. So, we would spend 3 to 4 months building a prototype and then show it around. All we wanted was for somebody to say that is pretty good. It might not work at this stage, but the customer thinks it is a good thing to have or if they didn’t then you would have to make changes. So say they said it was pretty good. We would expand the development with a bigger or a longer development period. Then again we would show it to customers for feedback. It might not be elegant, but it worked. Here again we wanted the “aha moment” from the customer. If we did not get the “aha moment” we knew we needed to make changes.