The development of retail business, characterized by the increasing number of modern supermarket, helped change shopping cultures and patterns. Originally, buyers shopping in traditional markets can communicate with the seller. But at the supermarket, buyers communicate with packaged goods on display. Check out counter, which is an area that the customers’ end their spending process, has become highly regarded optimization strategies by the supermarket manager. The data was obtained through observation at five supermarkets that were selected based on criterion, as well as in-depth interviews to the managers and structured interviews to the consumer. Data analysis was performed by means of a data matrix of the observation, the interview was associated with a theoretical review and research questions. The result that a spontaneous purchase process is influenced by external factors such as the display of patterns, shapes and packaging design, internal factors consisting of insight, lifestyle, knowledge, behavior and attitudes of consumers. The decision to buy is more influenced by irrational factors. The results of this study become an important information in planning the design of packaging and display, especially in the checkout area.