Patent ID: 8036947

Claim:
A non-transitory computer-readable medium having embodied thereon a computer program for operating a differential payment system connected to both a supplier terminal of a supplier providing a service and a purchaser terminal of a purchaser purchasing the service through a network, the computer program comprising: a membership information registration/management module receiving membership informations from the supplier terminal and the purchaser terminal, the membership informations being stored in a membership information storage member; a credit evaluation/management module creating a service credit information about the supplier based on the membership information about the supplier stored in the membership information storage member; a service evaluation/management module calculating a service evaluation score based on a service evaluation information input through the purchaser terminal after providing the service to the purchaser; and an installment payment price calculation module determining a ratio of a pre-installment price to a post-installment price based on the service credit information, the pre-installment price paid to the supplier before providing the service and the post-installment price paid to the supplier after providing the service being included in a service payment price paid to the supplier, the installment payment price calculation module calculating a differential post-installment price in proportion to the service evaluation score from the post-installment price after providing the service, the installment payment price calculation module transmitting an information about the pre-installment price, an information about the post-installment price, and an information about the differential post-installment price to the supplier terminal.