A sales promotion system of merchandise utilizing an Internet site, includes information providing unit for sending predetermined information to an information terminal device of a user via the Internet site. And the sales promotion system of merchandise further includes unit for calculating a cumulative total of charges or point values converted from charges paid in a predetermined period in exchange for information provided by the information providing unit, so that the cumulative total is used for deciding a rebate amount rebated to the user when the user purchases a specific item of merchandise.