Disclosed is a wireless communication system using visible light and, more particularly, a short-range wireless communication system using a camera sensor module and a flash module mounted on a wireless terminal. Because the toner sealing member is not damaged by the repeated mounting and demounting of the toner cartridge, toner is supplied efficiently from the toner cartridge, without leaking towards the guide frame. Additionally, the method includes determining a second estimate of the demand function for the item by utilizing a second auction using auction data from the first auction. The server encrypts the hash to generate a confirmation ID, and sends the confirmation ID to the software product purchaser.