Abstract: A first server (100) includes: a store-entry management unit (102) that, when acquiring first individual determination information about a customer who enters a store, generates second individual determination information for a second system separated from a first system for managing customer information, and stores the acquired first individual determination information and the generated second individual determination information in association with each other in a storage unit; a transmission unit (104) that transmits the second individual determination information to the second system; an acquisition unit (106) that acquires, from the second system, the second individual determination information and purchase product information being information about a product to be purchased by the customer; and an output unit (108) that determines the first individual determination information associated with the acquired second individual determination information, and outputs the first individual determination infor