HD (Digital) Radio May be a Boon to Advertisers
Everything is digital today. Your cell phone. Your CD player. Television. Now, it is radio's turns. As mentioned here earlier, HD radio is on the way.
Among many other things, it will allow advertisers to insert text and perhaps graphical images along with their typical 60 second commercials as the new radios will have a display panel similar to those now on automotive satellite receivers. On the most basic level, the ability to display an 800 number in a radio screen for the entire length of the commercial would greatly increase the chance that listeners would actually remember the number.
MediaPost: Ad Boundaries Changing as Radio Goes HD