If you're willing to spend a little bit, contract someone to build a site that offers the service and looks good, but only actually allows people to sign up for

If you're willing to spend a little bit, contract someone to build a site that offers the service and looks good, but only actually allows people to sign up for the future service or something along those lines. If you get people who are willing to sign up, then perhaps you could persuade someone to invest in the business and finish building the actual service via contract with someone else's money? At that point you could maybe leverage some sort of sale/investment where you end up being very hands off? Even if you were going to build it yourself, just making the site to confirm interest would probably be a good move. Reading "The Lean Startup" with a coworker right now. It advocates a lot for experimental validation before investing any engineering effort.