You are correct that there has been problems with a panel shortage and severe weighting. You are also correct that binge listening has caused some recent spikes, like that of WDAV.As has been mentioned, Nielsen has had a double PPM problem in the last two years.
First, the pandemic has caused many to drop off the panel. And it has been harder to get new panelists; the reasons why are varied by have to do with people not wanting outside contacts.
Second, the meters are made in Asia. Surprise to all, I am sure. Nielsen has been unable to get new meters for new panel households, so the sample is off in many ways.
The result is more erratic numbers for stations... 4.5 to 5.6 to 4.1 to 5.1 in four months. And, occasionally, some binge listening by a household causes a very strange peak like that of WDAV.
We have to keep in mind that ad agencies look at many combined books and get a feel for trends that are real before making a buy. So month to month wide variations average out, usually at a level that is the station's true rating.
In Diary markets, the issue is different: the slow-down of the USPS has cause many diaries to arrive too late to be "in tab" and are lost. In one market, a top 20 one too, there was a recent period where over a third of diaries were arriving too late to tabulate.
I will counter that there have been improvements in the panel numbers and less weighting in the last couple of months in Charlotte. I will also say that WEND is only on their third PD since the station launched in 1995, and he just started in October. There have been some changes on that station, and the increase can be explained. WDAV’s increase could not.
Time will tell if it’s binge listening or some of their changes are paying off.