I was attending a talk by Amnon Landan, who joined Mercury in 1989 and was CEO from 1997-2005. One of the things he talked about was how to decide whether a product idea was worth pursuing or not.
He made the picture above. When you build a new product, the first 10 customers or so like the idea of the product and the vision and buy it. Then come the implementations where rubber meets the road. The vision meets reality. The product always falls short. It has gaps, doesn;t work in all the cases etc. And usually the euphoria that came with the first 10 customers leads to stress and strain in the organization.
Someone in the audience asked, should you ditch the product at this stage or keep going with it. Amnon said the more the customer complain, the more you should build the product. Almost always the same customers will become your biggest champions once you have delivered.