The convenience and carrying capacity of shopping carts play an important role in the sales of a self-service supermarket. Inventor of the earliest model of the shopping cart, Sylvan Goldman of Oklahoma City, described his idea in 1939 as a "combination of basket and carriage." The frame he devised held two baskets and was like a folding chair with wheels. In 1946, Orla E. Watson of Kansas City, developed these telescoping shopping carts that were "always ready" and required no assembly or disassembly of components before or after use.
Watson's telescoping feature allowed carts to nestle into other carts for compact storage. Each additional parked cart, claimed the brochure, required "only one-fifth as much space as an ordinary cart," which meant more carts for shoppers as well as more retail space for store owners.