If the problem is well-defined, you can get a fairly strong signal on intent-to-purchase by asking for commitments (i.e., time, reputation, money, or secrets ab

If the problem is well-defined, you can get a fairly strong signal on intent-to-purchase by asking for commitments (i.e., time, reputation, money, or secrets about an enterprise buying process). You start with the smallest ones (weakest signal but easiest to ask for early) and then move up toward money (and eventually full price) as you make progress with the overall business. But if the problem is undefined/unknown (like much future tech), or if the product is a nice-to-have or "10x improvement" (like many B2C apps or UX improvements), then you basically have to validate via a prototype (or some other sort of creative v1). (You can still do your discovery/understanding via conversation in either case, of course.)