An advertising system and an advertising sign are provided in which the address on the advertising sign can be actively used, the advertising sign can directly serve as a buying and selling device, there is no interference in the advertising sign between the data transmitted simultaneously from a plurality of wireless devices, and the transmission direction of the electromagnetic waves or sound waves transmitted to the advertising sign is clear. The wireless device transmits a terminal address that indicates the address of the terminal to the sign apparatus, the sign apparatus receives the terminal address transmitted from the wireless device and transmits the received terminal address to the advertising server via a public network or the Internet, and the advertising server receives the terminal address transmitted from the sign apparatus and transmits the advertising data to the terminal having the address indicated by the received terminal address.