Abstract: A system for measuring exposure to a visual display such as a billboard. A transmitter that is proximate to the billboard broadcasts a data signal that carries information relating to the billboard. This information may identify the location of the billboard, the message displayed by the billboard, and time of day. The data signal is provided at a power level that is adapted to reach a pre-defined exposure area in which the billboard can be viewed. A portable receiving device is provided to a defined consumer population to measure the exposure of the consumers to the billboards. The receiving device may be carried or worn by the consumer, or carried in the consumer's vehicle. The receiving device is adapted to recover the data signal and store the information relating to the billboard when the viewer is in the pre-defined exposure area. The time of day and duration of the exposure may also be recorded.