The consistently excellent Edison Media Research have just completed a study of TV advertising for radio stations.
In many US markets radio ratings figures are calculated using PPMs – pager-type devices that record audio heard. This gives more granular ratings data based on actual consumption. It’s also something that’s turned round quicker than the usual diary methodology and provides per minute data.
What Edison have cleverly done is encode, in the same system, the TV ads advertising radio stations. That way they can use the same panel who are being measured for listening to the radio and also measure whether them seeing a TV ad has prompted them to listen to the specific radio station advertised.
The presentation’s below (and probably won’t embed email/RSS readers!) but they key finding seems to be that TV doesn’t do a great job for encouraging people to tune in for the first time, but does a good job of making moderate listeners listen more.