Abstract: A footprint-providing device which can put footprints on Web pages provided by various Web servers. The footprint-providing device is connected via a network to a client terminal that views a Web page with a browser. The footprint-providing device sends footprint data, which can be written on one part of the Web page that has been received by the browser of client terminal, to the browser receiving the Web page from a Web server as a response to a request that is made asynchronously with a view-request for the Web page by the browser.

Abstract: An affiliate system in which it is possible to form customers on the initiative of advertising clients is provided. Affiliate System 1 comprises Affiliate Server 10, Advertising Client Server 21, and Advertising Client Terminal 22. These are connected with a network. Affiliate Server 10 stores a reward-payment-was-approved bit string if received a reward-payment-approval-notifying bit string from Advertising Client Server 21, stores a check-was-done bit string if received a check-notifying bit string from Advertising Client Server 21, generates a market-data bit string using the stored check-was-done bit string if received a market-data-disclosure-requesting bit string from Advertising Client Terminal 22, and sends it to Advertising Client Terminal 22.

Abstract: A footprint-providing device which can put footprints on Web pages provided by various Web servers. The footprint-providing device is connected via a network to a client terminal that views a Web page with a browser. The footprint-providing device sends footprint data, which can be written on one part of the Web page that has been received by the browser of client terminal, to the browser receiving the Web page from a Web server as a response to a request that is made asynchronously with a view-request for the Web page by the browser.