An advertising compliance monitoring system is provided that includes a backscatter tag affixed to a sign or marketing material or shopper ID card, the tag communicating with a backscatter reader on a periodic basis. The tag includes a memory for storing tag data, a transmitter and a receiver. The tag uses sleep modes to conserve power. The tag transmits tag data to a reader automatically on a periodic basis or upon an event. The tag data includes an identification number used to identify the tag associated with a particular sign, price, marketing material or shopper, status data (e.g., delivered, displayed), and time and date information. This data is processed by a central server to determine compliance with and/or exposure to a particular advertising program.