Look, no one is disputing the need for commercial radio to run spots in order to hit their revenue targets. I am only disputing the current trend to dump 10 minutes of spots -- or more -- all in a row instead of spreading them out over the hour.
Again, that has been tried repeatedly, and it doesn't work. The problem is listeners like long music sweeps. When you distribute commercials throughout the hour, you break up the music sweep, which is the reason people are listening to a music station in the first place. Plus, if you break up the music sweep when your competitor is in the middle of one, you've lost a listener for a relatively long time.
In the old days, when I heard a spot break, I stayed with the station because I knew that it would be over in just a few minutes. Now, when I hear a spot break, I know that it will probably go on forever, so I change the station.
Listeners really hate tuning into a music station in the middle of a stopset. By distributing commercials throughout an hour, you increase the likelihood people will join you in the middle of a break. Too many joins during commercials means you never become anyone's favorite. Those who don't mind commercials, of course, might keep listening, but they'll listen through a standard break, too.
On a side note, do the advertisers really think that the majority of the audience is actually still listening by the time they get to the 8th or 9th spot in a 12 minute spot break?
Most stations have various priorities for clients and their spots. As an example, one of them where I worked had 11 potential such categories. Priority 1 was an exclusive paid sponsorship while Priorities 10 and 11 were barter and bonus spots respectively. The other categories offered something in-between with agency buys getting higher priorities than local direct. Advertisers know certain listeners will never listen to a full commercial stopset. While some do research and others don't, those who want to be in a specific position in a break can ask for (and likely pay for) that. The local direct buyers also knew they were a lower tier subject to being bumped for agency spots. We occasionally had advertisers who wanted to be the last spot in a certain break. They thought being last meant people who had tuned out at the first commercial were likely coming back because the competition had probably finished its music sweep by that point.