Dental Discount Plan - Business Plan

Okay so a friend and I are going to start a Dental Discount Plan business.

The advantage to the dentist is that he gets free advertising and customers he may not have gotten if he was not part of the plan. I know several dentists that participate in these dental discount plans.

I have come up with a list of prices I would like to use but was wondering if any of you out there have ever used such plan, or have any suggestions about running a business like this? Startup info mainly...

Thanks,