To reduce the time and cost needed for a product sale homepage.

A person who structures the product sale homepage accesses a sale center server 20 first (step B1) through a managing center server 40. In response, the sale center server 20 sends sale center setting information to the managing server 40 (step B2). The person who structures the homepage views various setting information displayed on the screen of the managing center server 40 and registers desired services to be provided on the screen (step B4). The setting information stored on the managing center server 40 is transmitted to the sale center server 20 through the Internet 100 (step B5). The sale center server 20 receives the setting information and alters the product sale homepage (step B6).