I recommend founders end customer discovery interviews by asking for a purchase (or a preorder/letter of intent, depending on the situation). This is the most immediate way to testing whether a customer's really willing to pay.
While I agree this is an excellent form of validation (perhaps the ONLY form of validation), this has to be done with extreme precaution.
Most customer discovery interviews are agreed to under the guise of "sure, I'll share some of the issues I face and give you some feedback on your concept."
When you turn the tables at the end and ask "wanna buy now?" you can instantly destroy any semblance of credibility and rapport you may have built over the course of the interview.
There is a very nuanced way of doing it that (in my experience) very few founders have the capability of doing...
i completely agree! when we were asking discovery questions, people tend to want to talk about the pain point and that gives you an illusion of validation. as soon as we ask, so how much would you pay for this? the conversation shifts and the true priorities come out.
