Costco and Walmart might not seem like the most logical pairing. The former occupies a special niche in the market, using the trappings of a warehouse and the allure of bulk supplies to entice customers to sign up for an annual membership. The latter competes with both traditional grocery chains and retailers​ of household goods, bringing the two concepts together under the appealing banner of a one-stop shop.But they do have their similarities. Both claim to offer consumers a wide selection of products with among the lowest prices on the market. And both have a devout customer base.​We compared them to see which most merits that praise.