The greatest Top 40 radio station of all time, the one that everybody copied played one song, one spot, one song, one spot, one song. The greatest radio station I personally programmed and the greatest one I consulted both carried ten minutes of commercials an hour and never more than 3 spots in a break. And they both made piles of money for the owners and both paid their people well above average. A different age, yes I know.
The long spot breaks originally came into being as a way to promote long music sweeps. That was a tactic of the (then) new FM usurpers challenging the established AM music stations. Over the years, the breaks got longer and longer and now they are near universal; every station is blowing off it’s own toes with them.
Here’s an interesting number. Pandora did some research on it’s ad content. A long sample period; 21 months. A huge sample base, 35 million listeners. Listeners were divided into 9 different groups, each receiving a set number of ads per hour. Finding: increasing the load by one spot an hour resulted in a 2% decline in average listening.