There's another dynamic: available cash. Someone low income will pay advertisers a lot less than someone high income. The radio payment plan is more progressive than anything the Feds ever concocted. In my case, it's 0.
No, it is NOT "zero"- unless your time is worthless- because you are either wasting your time listening to commercials for some stupid weight-loss product or a horribly expensive bed, OR you are tuning these out and twiddling your thumbs (or whatever). In either case, you are only getting 36 minutes of actual "show" per hour.
By subscribing, I can hear the entire 3-hour Rush show at anytime or place I wish (including at work), plus I can hear it in under two hours, because all of the "breaks" are trimmed out for me.
I make $50.00 + an hour- so I figure that I am actually MAKING at least $50.00 every time I listen!