https://marco.org/2010/02/27/since-businesses-are-obliged-by-zoning
Since businesses are obliged by zoning restrictions to locate far away from residential areas, most Americans drive to every store they visit. This means that store visits are often discrete trips that must be undertaken consciously and planned out ahead of time. As a consequence, shoppers will want to visit stores that carry the most diverse inventory—Wal-Mart, Costco, et al.—and avoid shops that specialize in one particular kind of good—the local paint store or flower shop, for instance.