[donkeyd]

It doesn't have to be a waste of time. The thing is, you don't need to have all the answers if you just pick a potential customer and work with them. We had this exact same issue and we helped them integrate the product, while also learning about their processes, which helped us sell the product later. This is an investment however, it doesn't make you any money and that customer will probably be a net loss in the short term and you need to accept that.