Convenience has always been the cornerstone of C-stores. But today’s version offers far more than cigarettes and lottery tickets. Many now offer a full menu of hot and cold food, for example. Some even offer other products and services. Add a self-service kiosk, and convenience evolves to the next level. A 2018 study by the financial news site PYMNTS.com found that self-service kiosks increase spending in quick-service restaurants by as much as 30 percent and C-stores are beginning to see similar results.