Google is allowing some of its existing online marketers to use its automated advertising system to broadcast ads on radio stations around the United States, the company said on Thursday.

The internet giant's move into radio advertising comes on the back of its takeover of radio advertisers DMarc Broadcasting last year. 

The test is set to include 730 stations, covering some 87% of the country and will allow advertisers to target their ads by geography, station type, listener demographics and time of day. According to Google's head of radio operations, Ryan Steelberg, customers can expect to pay a higher rate for more targeted an ad campaign

Google has been trying to expand its lucrative online advertising system to other markets. The company last year quietly ran a limited test in some magazines and last month announced a test involving 50 newspapers. This is the company's first foray into the radio advertising sector.

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