Take a look at this chart from Edison Research. According to their most recent survey, 76 million Americans listen to online radio at least once a week. And this just isn't local stations streaming their content. It includes services like Pandora, Spotify, Slacker, Rdio and others. And much of this listening is being done via smart phones. And a sizeable portion of that listening is being done in cars.
The bars in this graph are only going to get higher and higher. Traditional AM and FM stations need a digital strategy NOW. Otherwise they'll become so marginalized that soon, no one will care.