Midday on a Wednesday, Norman Jemal and his 7-Eleven field consultant, Kunta Natapraya, huddle around a computer in the back storeroom-office of Jemal's 28th Street franchise, poring over a tiny-fonted spreadsheet. Before them lie the stories of thousands of snacks consumed. Along with a sugar-free Slurpee Lite, 7-Eleven corporate is about to roll out an empanada, and Jemal and Natapraya need to make room for it by eliminating another occupant of the hot-food case here at 28th Street and Third Avenue, one of Jemal's three Manhattan 7-Elevens. Natapraya is something like a convenience-store social worker. He visits New York's 7-Eleven stores on a weekly basis to help franchisees improve their bottom lines and is their main point of contact with corporate.