Grocery stores, supermarkets, convenience stores... from name brands to mom and pop shops, the retail experience has changed drastically over the years. Self-service grocery stores however, both large and small, have remained largely unchanged since their inception in 1916 by Piggly Wiggly. The introduction of the shopping cart in 1937 by Sylvan Goldman, owner of the Humpty Dumpty supermarket chain, further upended...