Fast food companies love Columbus, Ohio. It's the perfect place to test products like the McDonald's McRib, and try out prototype Wendy's and Panera Bread restaurants. The city is located in the heart of the heartland after all, and companies believe its residents typify U.S. consumer behavior. For decades, its demographics have mirrored national numbers, though since it's the third-fastest growing metropolitan area in the Midwest, it's now more diversified than the nation overall. Even so, Columbus has held onto the "ideal test market" title for decades, and many businesses still choose to test there 1. It's a microcosm of...