I think this is a novel idea and I congratulate you folks.
One thing of a concern I have is negative marketing. What if a group of people have negative interest in a business and flood your website with negative-but baseless-comments? This has been plaguing other internet review sites and companies are deliberately doing it to make money out of "cleaning the reviews." I am curious if you had any plans to counter that or will just let market correct itself.
Good luck.