The chasm between what people say they are willing to pay for and what they will actually pay for is wide.
Here at THG, we often works with startups on using the lean startup process to help determine whether there is demand for their product before they sink significant time and money into development.
Customer development is a key part of this process. When doing customer development, the most common piece of advice we give is to make sure you are getting real commitments from potential customers. The chasm between what people say they are willing to pay for and what they will actually pay for is wide.
When testing an idea on the market, act as if you already have the product and try to complete a transaction. Get your customer to pull out their cash or credit card and pay you. You won’t necessarily keep the money they give you, but if your product is compelling enough to part customers from their cash, you may have found a problem worth solving.