Thanks to the Ad Council (itself a charity), charity ads fill in when commercial advertisers pull out of raunchy radio shows.
The surprising charity support for hot talk radio came to light deep in a story in the New York Times (Jacques Steinberg & a cast of thousands), whose reporters listened to various talk shows for a week to see whether the fall of Don Imus has had any effect on other popular hosts of the mean and nasty stripe.
What they heard on Mancow's Morning Madness (syndicated out of Chicago), along with a conversation where a caller was labeled a "brain-dead fetus," was an ad for the American Council on Education (EIN 53-0196573 Form 990). Most likely it was a radio spot (like this MP3) for KnowHow2Go, a current campaign that encourages low-income and first-generation student to go to college.
This was news to the representative of the ACE, who said that the organization had nothing to do with the ad placement, which was handled by the Advertising Council (EIN 13-0417693 Form 990). The Ad Council, which is a 501(c)(3) charity organization itself, prepares public service ads for charity organizations, which are distributed to the media, which today can be as simple as posting them on a public web site, like this one.
What this means is this: while national advertisers can pull their ads from programs they don't agree with, charities working with the Ad Council don't have that right. Public service announcements can be used to fill in when the national advertisers pull out of crude and unseemly radio shows.