Most people have no idea how radio stations are rated. Movies are all about box office and Rotten Tomatoes schools. TV lives and dies by Nielsen ratings. Newspapers and magazines have circulation numbers. But how does the industry determine which radio stations are popular and which aren’t? It turns out that the oldest form of electronic media has the least reliable ratings methods.
The first is known as the “diary method.” A statistically valid number of people are chosen to write down what radio stations they listen to (and for how long they listen) in a paper diary. The survey lasts one week. This is highly imperfect because it demands a person to recall where they were when they listened to what station and for how long. To get an idea of how difficult this can be, try to remember what you had for lunch last Thursday. Since most people fill out their diaries at the end of the week, the returned data consists of what people think they were listening to, not what they were actually listening to. Radio people hated diaries, but the generated the ratings by which stations and careers lived and died.
In some markets, diaries were replaced by PPM–personal people metres. A statistically valid number of people are paid a stipend to carry around a pager-sized device that detects whenever a radio station is being played within a certain range. Radio stations encode their broadcasts with a special signal that only the PPM can hear. At night, the user is supposed to dock the device whereupon data is downloaded to a central site where they’re stored and crunched and released to radio stations every month.
PPMs are better–we think–than diaries, but they also have their shortcomings. For example, they measure exposure to radio not necessarily listening. For example, if you work in an office where someone else has control over the radio and they like a station you hate, you have no choice but to be registered as a listener of that station. If you’re walking through a store and your metre picks up what the station the store is playing, you get registered with that station. Maybe your metre is deep in your purse or in the pocket of a thick jacket. Maybe you forgot it at home one day. And it’s damn hard to get certain demos–especially young men–to carry these things around in the first place.
Bottom line, though, is that radio folks in large markets like Toronto live and die by the data these metres return.
This brings us to the new controversy over a device called Voltair. It’s a new processing box that juices the encoded PPM signal, making it easier to be detected by PPM metres–and they seem to work very, very well in some cases. These $15,000 boxes are installed at individual radio stations and not at some central facility.
You can begin to see the problem. Stations with Voltair boxes might have a distinct ratings advantage over stations that don’t. The question becomes one of a level playing field. And if you really juice your PPM signal, it’s possible that metres will become so sensitive that they’ll pick up whatever the guy next door is listening to, which leads to warping of the ratings. In other words, an individual station’s ratings may increase but the numbers could be totally bogus–just like we saw with diaries.
Numeris–the company responsible for gathering radio ratings in Canada–has asked that all radio broadcasters cease and desist using Voltair boxes until they can study the matter. Meanwhile, US broadcasters continue to be freaked out by the whole thing.