Read this blog post by Stacy Miller. Her argument makes perfect sense. She states:
I have yet to meet anyone that goes to the grocery store (‘farmers market’ branded or otherwise) to connect with their neighbors, create meaningful relationships with farmers, taste produce that was picked that morning, or ask questions about where and how their food was grown or how to prepare it. For these things, people seek out farmers markets, where they can watch first-hand the power that their dollars have in nourishing local entrepreneurship and sustainable growing practices.