You can build based on your traffic a fee for backlinks based on industry and it could be a price list for 1 star, 2 stars, 3 stars, ..., 5 stars.

By saying so you can stimulate entrepreneurs and blogers to engage people to vote on a small widged you can build and put on their website in order to pay less if they have 5 stars and more to have the traffic needed to grow if they have a ratio of 1 star.