Nielsen Broadcast Data Systems, better known as BDS, is a service that tracks monitored radio, television and internet airplay of songs based on the number of spins and detections. The service, which is a subsidiary of ACNielsen provides the basis for VNU Media publications Billboard, R&R and Canadian Music Network (discontinued in 2005; now a website) magazines in determining their radio airplay music charts and determines the chart movement in Billboard ' s Hot 100 chart when combined with single sales from Nielsen SoundScan.

Using a patented digital pattern recognition technology, Nielsen BDS captures in excess of 100 million song detections annually on more than 1,400 radio stations in over 130 U.S. markets (including Puerto Rico) and 22 Canadian markets. Nielsen BDS also uses the service to track monitored airplay at satellite radio (XM and Sirius), internet services (like Yahoo! and AOL) and audio networks (like Music Choice and Radio Disney), as well as on TV (12 U.S. music video channels and 8 Canadian video channels).

Since its 1992 debut, BDS has become the standard for the radio and music industry because of its accuracy of detecting, tracking and monitoring songs, thus eliminating the use of reporting and call-outs to trades and record labels when it comes to adding and testing tracks. The method has also helped tracks that only received airplay(songs that are not released as singles) become major hits, especially in Billboard's Hot 100 chart, where several radio-only tracks have reached the top spot.

BDS helps determine the Canadian BDS Airplay Chart, which is published by Jam!.