Following its moves into both magazine and newspaper advertising, Google is now preparing to go into radio. According to Reuters, the company has begun hiring sales people and plans to launch the Google Audio Ads service by the end of the year. Like the magazine and newspaper offerings, participants would upload their audio ads through the same AdWords Web application used to post text ads.

Google Audio Ads was made possible through the company's $102 million acquisition of radio advertising agency dMarc Broadcasting in January. So far, XM has agreed to allow some of its own advertising to be available through the service, and it is rumored that Google may be in talks with radio giant Clear Channel Communications to purchase as much as $1 billion of its advertising inventory.