Customers enter a 7-Eleven "Kwik-E-Mart" in Dallas, Sunday, July 1, 2007. Over the weekend, 7-Eleven Inc. turned a dozen stores into Kwik-E-Marts, the fictional convenience stores of "The Simpsons" fame, in the latest example of marketers making life imitate art. The store sells items that until now existed only on television: Buzz Cola, KrustyO's cereal and Squishees, the slushy drink knockoff of Slurpees.