Effectiveness evaluation method for web content, web content retrieval method and web content accounting method using the same, and retrieval server and content providing device

A method for retrieving a content requested in a retrieval site connected with a client via a network, comprising the steps of:

• accessing said retrieval site with said client;
• measuring a status of viewing one content by said client, and calculating the utilization rate of said one content from said measurement result acquired by sending the result to said retrieval site;
• and
• transmitting a retrieval result to said client according to the utilization rate of said content.

An accounting method for content of a Web site connected with a client via a network, comprising the steps of:

• accessing said Web site and displaying the content of said Web site with said client;
• measuring a status of viewing one content by said client and sending the result to said Web site;
• calculating the utilization rate of said one content from said measurement result;
• and
• calculating an amount to be billed from said utilization rate and general charge of said content.