Good points. But how many customers you talk to is enough? If I'm building a product for enterprise, is talking to one keen potential customer enough? For a fir

Good points. But how many customers you talk to is enough? If I'm building a product for enterprise, is talking to one keen potential customer enough? For a first time founder, I can't imagine someone without much connections can get the chance to talk to multiple potential enterprise customers. What about a product targeting the mass market, if I'm building a mobile app, is talking to a dozen friends enough? or should I pay for a market research which can reach hundreds of strangers. Do you talk to customers with prototypes of the features or do you just have a basic skeleton and say 'what if I have this and that'? I actually subscribed to Amy Hoy's mailing list but haven't checked it out for a while...