Build it and they will come? No, ask them if they would use it — in fact ask them if they would buy it right now and for what price — then build it. Any talk i

Build it and they will come? No, ask them if they would use it — in fact ask them if they would buy it right now and for what price — then build it. Any talk is cheap. Charge them for it as a pre-sale to really lock this down. Give them a reasonable discount if they prepay during the development period, of course, and refund everything if you can't deliver as promised for any reason.