> although how you had the time to sign up thousands of retailers and no time to build the product into a usable state confuses me
They don't need to "sign up retailers", just join their existing affiliate programs. Affiliate networks like Commission Junction get them 1500 merchants and 62% of the top 500 retailers just by clicking some buttons. I'm sure you could establish relationships with the top affiliate programs fairly quickly while personally contacting very few of them. Now skim off some of the commission while paying the rest to your users as rewards, and you have a business.
They don't need to "sign up retailers", just join their existing affiliate programs. Affiliate networks like Commission Junction get them 1500 merchants and 62% of the top 500 retailers just by clicking some buttons. I'm sure you could establish relationships with the top affiliate programs fairly quickly while personally contacting very few of them. Now skim off some of the commission while paying the rest to your users as rewards, and you have a business.