1. A point service system for offering various point services over a network in accordance with the number of points possessed by a customer, said system comprising: a point service provider server for keeping track of the number of points on a customer basis in a customer information database; a user terminal; and a trade service provider which is connected, over the network, said point service provider server and said user terminal, wherein said trade service provider comprises: deal request reception means for receiving a point deal request from said user terminal; deal making means for making a predetermined deal based on said point deal request; and point change means for changing the user's number of points which is kept track in said customer information database when there occurred a change to the user's points due to the deal made by said deal making means.