The idea is to prevent free riders in a commodified market and allow for collective action. It's actually very similar to a union in that each individual membe

The idea is to prevent free riders in a commodified market and allow for collective action. It's actually very similar to a union in that each individual member (or farm) is small and can't have much effect on their own. By organizing collectively you can become more powerful but there's no incentive for any individual member to join. Think about the "Pork, the other white meat" or all the milk mustache ads. A single farm could never put that together but by working together they can benefit the industry as a whole. So that's how you end up with these "checkoff" organizations and arguments against right-to-work laws.