they’re almost all owned by the same parent network (iheartmedia, which was clearchannel) so it’s stupid easy to coordinate

I remember always switching to another channel when ads came up, but later that became impossible because they all started ads at the same time. So it seems to be on purpose to prevent people from switching channels. This was in the Netherlands, though I haven't listened to radio anymore since Napster came out.

Some breaks are mandated by the FCC for station identification. These “Hard Breaks” are at the same time on all stations.

A lot of them are owned by the same companies. And they want engagement with their ads.

Because 90% of American Media is owned by only like six corporations. Radio stations a lot of times are owned by clear channel they all have a very similar programming structure.

I’m just speculating here... but suppose a station were deliberately out of phase with most other stations. When other stations go on break, frustrated listeners would search for different stations and find the out-of-phase one. They’d listen to that station until its next commercial break, at which point they’d repeat the process and return to their previous stations. The out-of-phase station would get a reputation as the station for listeners who always change stations at ad breaks, which would make it impossible for that station to find advertisers.

iHeart owned stations just play a fuckton of commercials, period. But there is also a requirement to play the station's call sign every so often, and they usually throw in commercials along with it.

All stations, TV and radio, get huge amounts of money from advertising. So they maximize commercial time to maximize revenue. Hence all stations go to commercial breaks around the same time. It's a formula. If you look at TV shows from the mid 80's and early 90's, you'll see 2 commercial breaks per half hour. Now you see 3 breaks per half hour and about every 7 minutes during hour-long shows. These same rules apply to radio, however they don't really have "shows" anymore. Just hour long segments interrupted by ads about every 3 songs.

They base their broadcast around hourly cycles put onto this day's frame, let's say it's a 12h circle like on analogue clocks, or a pizza. Each cycle starts with a jingle and ad, so you can divide it into equal 12 parts and eat a 5-minute slice from each. Then you have standardized blocks to peg into them, e.g. 2-3-minutes songs, ads, news blocks, longer blocks to occupy the whole hour like Car talks with Martok etc. Some of them (news, ads, jingles) repeat every hour or two making it trivial. There's not many ways to slice this pizza, so many of their plans naturally overlap. Iirc on music stations it's performed-semi automatically now, the machine can compile a plan to fit pieces from your music library and other components by itself.

In general, it is my understanding that most radio stations want to have something happen every fifteen minutes (at least), which is to say that it's very likely for stations to take their commercial breaks around the same time.

Probably a bit of both. Stations change personnel every few hours, typically on the hour. Depending on the programming, that may be more or less likely to be a commercial break.

Marketing research probably has strong indicators for when the most people get in their cars or turn on the radio at home. And they know that people tend to change the channel until they find music, and then are much less likely to change it during their commute. If your competition is on commercials, you can either also go to commercial, or you can try to steal those listeners with content.

I don't know how common it is now, but I know stations used to have syndicated programming as well, so they would have a local DJ or prerecorded local identifyer between songs or other content, and then the content would come from a regional or national feed. I know PBS works this way, because there are places where you can tune into different public stations and hear the same content. But to do that, you would want standardized, predictable commercial timeslots. Modern network communications and automation could probably eliminate that need, though.

And of course there's always coincidence. You remember the times when you happen to flip through stations and hear only commercials, but you quickly forget the times when you only have to change one station. You don't even know how often every station you're not listening to will go to commercials while you're listening to music. So there is a significant confirmation bias.

Hotelling's law

After a lot of thinking I purchased an external antenna, a radio transciever and a QRM remover to listen to foreign radios from Peru, Bolivia, Uruguay, Argentina and somewhere from the Carribean sometimes depending on the weather... Those are not corrupted... Every town or local radio are concentrating their efforts to get any money that not evolves curating good tunes. Hope you find a suitable radio station for you somewhere in the air or in the web.

We estimate we can sell up to 80% of airtime before inducing seizures.

Relevant video https://www.youtube.com/watch?v=KpPE85Jogjw

Radio ads were why I switched to Spotify years ago. Though when Spotifys ads started being a little more intrusive I switched to Plex and Plexamp. My next switch may be jellyfin and Finamp.