To provide a service in which purchased books held by users of the service are collected by using the Internet, and the distribution of the books collected by traders can be requested by using the Internet by the users of the service.

The list of the predetermined books with insufficient inventory of the traders and the predetermined books with high demand by the users is presented on the Internet, and the purchased books of members and applicants for membership are collected. The traders solely controls the inventory data of the books in the database, and makes public the inventory list on the Internet. The users refer to the public inventory list, select the desired books on the Internet, and request the distribution to the traders. The traders who receive the requests arrange the distribution, collect the distributed books in a predetermined period, and control them again as the inventory. A continuous service can be provided without any purchasing cost.