Zapier (YC S12) did something similar to determine demand for their initial product. I heard Bryan Helmig (co-founder) give a great talk on the subject, and it

Zapier (YC S12) did something similar to determine demand for their initial product. I heard Bryan Helmig (co-founder) give a great talk on the subject, and it seemed to work very well for them: https://zapier.com/blog/anatomy-of-sale-or-how-andrew-warner-became-our-first-paying-user/ https://zapier.com/blog/anatomy-of-sale-or-how-andrew-warner... http://bryanhelmig.com/bootstrapping-an-idea-the-paid-beta/ http://bryanhelmig.com/bootstrapping-an-idea-the-paid-beta/