If you were to isolate adults under the age of 30, I bet the degradation is significantly steeper than that.
Actually, 18-34 is a lot better than teens, although not as good as 25-54. Remember, stations don't target teens as there is no ad revenue there... and there has not been for 30 to 40 years back.
But hey, keep living in denial! It's served your industry great. Remind me, how much has radio revenue declined over the past 10 to 15 years?
Radio is still the largest circulation medium, and is very cost efficient. No, it is not what it was in the 90's and even up to the end of the following decade.
The biggest impact on radio in the markets where most of the revenue is obtained... the top 50 markets... has been the PPM, which cut time spent listening by over a third. And that cut revenue, based on CPM or CPP, by a third. Add in inflation and new media, and you have a bunch of big changes. Radio has a different focus based on the money demos wanting different things than my generation wanted.
I see a gradual transition to national network formats, with little local music programming being done. That is how most of the Americas and Europe and other nations where there is free radio do it. We have the technology and the financial pressure, so this will be done very soon.
I'd say 20+ years. I attended high school in the mid 90's. We were HOOKED big time on our favorite radio stations (Top 40, alternative, hard rock, or hip-hop as the case may be).
Yes, and nobody wants to have teen listeners. In fact, having too many teens will negatively impact station revenue in some ad categories.
And don't confuse the AM and FM bands with content. Radio stations can move to other distribution channels when it is important to do so; we are in the content business, not the transmitter and tower business. The only reason why this has not fully happened yet is that the costs of digital streaming don't allow any free digital content providers to make money.