AM v. FM Radio

[Kirk]

DavidTHR's post got me thinking about something I've wondered about for years. Why are there SO many commercials on AM radio versus FM radio? Does the AM transmitter cost more to run than an FM transmitter? Are the "personalities" paid better? Do the AM stations pay more for the syndicated shows they air? Anybody know?
Kirk

 

[Frangible]

There's a competition for "most songs between ads" of sorts in the FM world that doesn't hold up for talk radio, which is able to take more frequent breaks.