Systems and methods for collecting viewership data of television and radio broadcast programs. The methods include receiving an AV signal of a broadcast program and supplementary content which contains a tag identifying the broadcast program. The supplementary content is combined with the AV signal to form a data-augmented signal which is subsequently modulated with a carrier signal to form a transmit signal for broadcasting to receivers. Each receiver includes a decoder for extracting the supplementary content and recording the tag identity and time the tag is received. The recorded information is subsequently output to an electronic device or sent directly to a viewership data collection entity.