If I worked at New York magazine, I'd spend the day cross-referencing people hair-rending on Twitter about the magazine going biweekly with the subscriber list. Just saying.
Looking at the MPA data for New York magazine gives one small side of the story. Sampling Q1 and Q3 data since 2006, actual reported print revenue doesn't change that radically, at least since the Great Downturn or whatever we're calling it.
But total ad pages per quarter does change.
What's interesting is that the magazine, like, you know, lots of magazines, makes lots of money. According to the Times, going biweekly "will yield about $3.5 million in savings." (Not clear over what period that is.) Well, New York made $81,220,636 in the first half of 2013 on print advertising alone. Averaged out, that's revenue of around $3 million a week—and we're not even counting online ad revenue. So it's a hard game to trim your ability to actually deliver print advertising while still raking it in.
UPDATE: I didn't include my usual disclaimer about these numbers! Please blame it on "Monday morning." The Magazine Association numbers are like, basically, "rate card times number of ad pages." So while the ad page number is accurate, the revenue number is pretty much like saying "oh x website had 10 million pageviews, and their CPM is $12, so they must have made $400 billion dollars." We all know in the real world it doesn't work like that. The trending is useful in its way, however—more like an expression of "maximum total possible income."