That is a great question and one that many, many people ponder about. "if I build it will they come?" I have built over 10 MVP's and did some basic testing to see if I could validate the service. My suggestion would be to put together just enough of an MVP or test site to get your point or value prop across. Then I would set a budget for ads or facebook or some targeted demographic marketing and test the feedback and the conversions. You can actually fake it till you make it. You do not have to always deliver on what you are building. I can speak more to this in a phone call if you want... - JJ