Nielsen Audio is shutting down its RADAR service, which was used to measure network radio ratings. The decision was made because the vast majority of national network radio is now transacted on Nielsen’s Radio Nationwide service. RADAR was unique in that it provided commercial ratings, but over time, the demand for the service dissipated. Nielsen is still examining how it will continue to monitor spot clearances for network radio. Nationwide is a data-only service that provides audience estimates across each of the 210 Designated Market Areas (DMAs) in the contiguous U.S. as well as Alaska and Hawaii.