How much of that audience is older than 50?
True, but how many of those stations have audiences that are attractive to advertisers? Not counting non-comms of course, maybe 10% of AM and 70% of FM stations, roughly?
Only if you have a radio that will tune those HD channels. I have two at home, but not in my car. And I have no plans to buy an after-market stereo for my car anytime soon, if ever. Nor am I in the market for a car that has it.
Are those radios being developed now? Is the required infrastructure currently being developed and under test? If not, I wouldn't hold my breath waiting for them. Who's buying radios anyway, at least not that aren't a part of something else, like a car.
Maybe, but a lot of what you're saying can be filed under "pipe dreams." And I'd love to have some of what you're putting in that pipe.