Here you will find information regarding online radio usage.  Included is data from the comScore Arbtitron Online Radio Ratings, which is the only like to like audience metric to traditional radio.  Also included here is information about Dynamic Logic, a marketing research company that has gauged the advertising effectiveness of the Ronning Lipset Radio network. Finally, Ronning Lipset Radio subscribes to Mediamark Research (MRI) which looks at the qualitative characteristics of the online radio listeners.

Research From Arbitron
Arbitron/Edison Infinite Dial Study 2008 (Presentation)
Arbitron/Edison Infinite Dial Study 2008 (Webinar)
Current Monthy Audience for Ronning Lipset Radio
September 2007 Ratings Ronning Lipset Radio Breakout
Glossary of terms from Arbitron
comScore Details of Measurement
Consumer Studies from Arbitron/Edison Media

AdIndex (PDF) Read Dynamic Logic's New Research Application For Your Online Radio Campaign

Mediamark Research and Intelligence