PROBLEM TO BE SOLVED: To secure funds for facility investment costs on an Internet service provider (ISP) side that increase along with video (content) delivery in addition to a transit charge, and set an optimum value for a content charge, without incurring upon a content provider (CP) a reduction in the quality of delivery services provided.SOLUTION: The present invention is such that, in a chargeable delivery type content delivery service for which a content delivery charge is collected from a user by a CP, and in an environment in which two ISPs, ISP-1 and ISP-2, exist, the ISP-1 introduces a content charge for collecting a certain percentage (α) of a content delivery charge from the CP, and when the ISPs employ a transit charge for collecting the transferred amount of data raised to the power of &bgr;, each of the ISPs sets, in an inter-ISP competition environment in which the ISP-1 and the ISP-2 can freely set charge rates α, &bgr;, an optimum charge rate so that their own earnings are maxim
