Abstract: An on-line shopping system is provided which enables users to do shopping by referring to on-line advertisements posted on home pages. A WWW server and an exchange are connected in one-to-one correspondence. The exchange finally receives a PPP dial-up from a user device and thus can be informed of the originating number of the user device. First information about the connection of the user device to the WWW server is stored in storage unit after the transmitting port number accompanying the first information is converted to a corresponding line number. Also, second information (originating number) about the connection of the user device, obtained at the exchange, is stored in the storage unit together with a line number. In the storage unit, the first information and the second information are combined through the agency of the line number.