Abstract: The invention provides a server for managing, for each user, purchase result, replacement result and frequency of use of a consumable used in an office equipment, and capable, in managing the purchase result of the user, of providing a system of managing the kind and the amount of the consumable in detail and providing a discount service for the purchase of the consumable different for each user according to the managed information, or a system of managing the state of use of the consumable for each user, calculating the demand estimate for the consumable specific to each user according to the managed state of use and providing a discount service to the user according to the calculated demand estimate.