> Comments?
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Mid-book trends are always dangerous to depend on, or even to give any credence.
A format change will create a temporary sampling spike (watch what Jack does in the NEXT trends) and distort not only the format changer's numbers, but all of its competitors, before more normal and lasting listening patterns set in a few months down the line. And for news/talk stations, the news cycle makes a difference (look at the temporary spike most principal news/talkers enjoyed last year, and look at how they've come back to earth since November). And the potential for skew in any 30 day sampling in terms of diary distribution, response rate or demographic reach can also create the appearance of some strange listening patterns, until the following months' samplings smooth things out over the course of the whole book.
I know Arbitron is just trying to please the stations and agencies who are its customers and want instant gratification---and instant validation for any tweaks made. But the rolling trends, unless they're read over time and taken in full context over months of samplings, can potentially do us a disservice by misleading us about what's really going on.