Nielsen Media Research has significantly increased coverage of the US radio market by its ad-tracking unit Nielsen Monitor-Plus - notably the debut of brand-level data to radio statistics.

Using 'electronic fingerprint' technology, the system now embraces over five hundred radio stations in the top twenty-seven markets. It does so on a 24/7 basis, reflecting a growth of 68% in the industry.

Monitor-Plus now covers 50% of all US advertising spend. Coverage includes 26 major US cities, among them New York, Los Angeles, Boston and Washington DC.

Says svp Jeff King: "We are delighted to make this enhanced capability available to our clients."

The top three radio spot advertisers in January 2005 were ...

1. Insurance firm Geico with 38,000 commercial airings;

2. Fox TV network (34,000);

3. McDonald's Restaurants (33,000).

Data sourced from BrandRepublic (UK); additional content by WARC staff