In order to prove or disprove the concept without actually building out any kind of CMS or infrastructure, I set up a marketing site and some demo restaurant mobile sites (really good looking stuff built on jQTouch). Next step was to build prospect lists with every OpenTable restaurant in a handful of Ohio cities (I live in SF now, but was in Cincinnati at the time) and do a ton of cold calling.
After hundreds of pitches at different price points, I only managed to sell a few at $49/year and decided not to pursue any further. Having little prior sales experience (sold CUTCO as a high schooler) was a problem for me. Timing is crucial and being too early was another likely inhibitor. Figuring out the best sales channel is may be your biggest challenge. Along with how best to pitch the restaurants, who are not traditional early adopters.
I'll be keeping an eye on you guys. Best of luck!!