Audio4cast

Arbitron recently posted October and November audience reports for seven online radio networks on its website. In November, Arbitron reports that the cume of the entities that they measure is close to 8.5 million on a weekly, Monday to Sunday, 6am to midnight daypart.

The Targetspot Internet Radio Network is the largest measured network on the report with a weekly cume of  5.5 million and nearly 450,000 AQH. That network includes 4 of the other, smaller networks on the report: CBSRadio, Yahoo/Launchcast, Live365, and a small RL Select sub-network. CBSRadio ranks second on the report as a standalone – including the AOLRadio audience which was absorbed into that network during 2008. A newcomer to this report, ReplaceAds, takes third place on this ranker, with a cume of 2.2 million, and Clear Channel’s Online Music and Radio network has a cume of close to 1.6 million.

Source: Arbitron

Arbitron’s online audience measurement is obtained from web research company’s comScore’s panel data, which Arbitron licenses, utilizes and rebrands as its online radio product. The service measures only subscribing entities, which makes it impossible to draw any conclusions about the total Internet radio listening universe.