BigA, saying that what worked on radio 40 years ago won't work now, is like saying people won't eat a Big Mac, because it's so 50 years ago.
If the Big Mac was made 50 years ago, nobody will eat it. The medium of radio is 100 years old. THAT is the mechanism that stays the same. But clearly the audience is looking for different things from that 100 year old mechanism. Pizza may be 100 years old, but it's not the same kind of pizza they made back then. They didn't put chicken or BBQ sauce on pizza 100 years ago. Today, people can get local news, local weather, and local traffic from a lot of different places. Radio doesn't have an exclusive on that any more. Lots of places make pizza. Lots of hamburger places. What distinguishes one place from the other? So you have to consider there's really nothing they can ONLY get from terrestrial radio.