Each month Nielsen releases client PPM 6+ rating estimates to the world, and each month we read numerous analyses of who’s up and who’s down.
While the monthly rating play-by-plays are widely read and taken seriously, they shouldn’t be.
This is the sort of analyses we see:
WHTZ was up to #2 for the first time in over a year but with only a slight increase of share.
WLTW’s 6.0 in July was its lowest 6+ share since November 2014. Its +.1 (share) in August halted four successive declines with a cumulative loss of seven-tenths.
WSKQ tumbled for the third successive sweep, a combined -1.4 since June, drifting from third to sixth.
This is the wrong way to look at Nielsen estimates. We all would like to believe that monthly numbers reflect reality, that the number one station really has more listeners than the number two station, but that’s not the case.
The ratings are not month-to-month battles between stations to be analyzed like a horse-race.
Stations inch ahead in the monthly trends not like horses but rather like heads and tails in multiple coin tosses.
Month-to-month rating changes are random. They are no more predictable than whether a coin toss “winner” will be heads or tails. It’s something we’ve addressed here, here, here, and here.
That’s why wobbles are not rare events. And the wobbles can be great enough for stations to swap positions from month to month.
Even New York with its 4,000 daily in-tab doesn’t have a large enough sample to prevent month to month swings in rank.
To illustrate the degree to which uncertainties can impact month to month changes, we took a close look at recent New York numbers.
The first graph reflects the way station ratings are typically reported emphasizing month-to-month changes.
We’ve graphed the 6+ numbers for the top five New York stations trended from June to August.
As you can see, even top rated New York stations go up one month, drop the next, then repeat the process month after month.
For example, WLTW started the period in first place, fell to second one month, and rebounded the next month.
Meanwhile WCBS-FM started in second, wobbled its way to first in July, and ended the four months right where it started.
A much more useful way to look at monthly PPM trends is to look across the same months in previous years. Are stations ahead or behind where they were one or two years ago?
To make comparisons even more useful we can average three month’s numbers, a quarter’s worth of estimates. It won’t eliminate wobbles, but it will temper their impact.
The second graph is the result.
It shows the same five stations, but here we’ve averaged three months and compared the three months to the same months in the previous three years.
Looking at the numbers this way gives us a completely different view of what’s happening at the top of the New York ranker.
The first thing that jumps out is that four of the five stations are below their 2013 numbers.
Worse than that, three of the five stations are at their lowest point going back four years, some significantly.
One notable oddity is that four of the five stations spiked in 2015, only to fall again this year. Why would four of the top five stations all spike simultaneously?
It is unlikely that all four 2015 spikes are real.
Share is a zero-sum estimate. It always equals 100, so for one station to go up, some other station goes down.
Even with WSKQ’s growth, more than two shares evaporated from the top five New York stations in 2016. It's hard to believe that four out of five of the top New York stations would really tank all at the same time.
And what about Mega 97.9's steady growth over five years?
Recall that quote from one of the analyses, "WSKQ tumbled for the third successive sweep, a combined -1.4 since June, drifting from third to sixth."
The steady growth of the station over the past three years puts that “tumble” into perspective
It’s an example of why month-to-month comparisons can be so misleading. None of this was apparent from the monthlies.
We kept this analysis to five stations to make it easier to see what’s going on. Now that you’ve got the idea we’ll dig a little into New York numbers as well as other markets in future posts.