The network server stores the order information and the customer information received from the order entry channel in a database with identification information of the retailer system that has mediated the order, extracts, in response to a request from the retailer system, at least one of the order information, the customer information corresponding to the identification information of the retailer system having made the request, and information obtained based on at least one of the order information and the customer information from the database, and provides to the retailer system. The network order system includes the network server for receiving and managing at least the order information.