Back in the 1990's the NRA couldn't pay to get ads in many major publications. The ads would not be accepted even when offering to pay above the existing ad rates (and most ads are discounted from the published rates). Just like a black person trying to eat a meal at a whites only restaurant in the deep south fifty years ago--their money wasn't any good with the bigots in control.
New York, with it's extremely repressive gun laws, is the home of much of the U.S. print media and hence management had an inherent bias against gun ownership. But it appears times are changing:
I wonder how much of it is because the print media is a lot hungrier now or if it is because of the Heller decision and the fact that guns are more accepted now.