Store operations Many Trader Joe’s stores could be found in old strip malls in suburban locations. The typical Trader Joe’s store had less than 15,000 square feet of selling space. Many early locations maintained footprints of approximately 10,000 square feet. The typical supermarket ranged in size from 40,000 to 50,000 square feet. As a result, Trader Joe’s did not have the wide aisles that existed in many supermarkets. Writer Dave Gardetta explained the logic of the quirky, cramped layout of the stores: