An advertising control method is described. The method includes receiving an advertisement identification message (AIM) at a first mobile device, sending the AIM from the first mobile device to a content display unit (CDU) and storing the AIM in the CDU, selecting at least one content item from among a plurality of content items based, at least in part, on at least one stored AIM, the stoned AIM being stored in the CDU, and displaying the selected content item on the CDU. Related apparatus and methods are also described.