The research has unfortunately long indicated that people who listen to country music lean to lower education levels, and lower incomes.
Sure, but you could say the same thing about people who listen to hip-hop and Spanish language stations, and there are a multitude of them on the NYC radio dial.
Spanish language and hip-hop stations draw advertisers who are specifically interested in reaching Hispanic or "urban" groups, with the money budgeted in those directions from the get go. Or the advertising is sold to businesses within those communities, like ethnic food companies, or hip hop clubs.
Country stations, on the other hand, are in competition for advertising dollars that are aimed at the wider more generic population, and are therefore in competition with other music and spoken word formats for the same business.
While it hopefully is true that the big media buying agencies acting on behalf of major national advertisers now just go by a formula of demographics, ratings and spot price, Country stations usually look for a lot of regional and local advertisers and that is where this perception of poorer than AC, or all news listeners can become a problem.
It has been years, but I heard the same story from Country station sales managers, GMs and even owners, that it was tougher to sell spots on the Country station than it was on the say "soft rock" stations because of a perception that Country fans were more likely pickup truck driving, hard drinking...you know the stereotype....etc. So the local Honda dealer was more interested in selling Accords to the higher income junior executives and computer programmers who listened to soft rock, than to the guys who worked on the loading docks or drove the trucks and listened to Country. That kind of thinking may have been more prevalent in certain markets where Country music isn't as popular and really represents a minority audience, as in NYC, and it may be a diminished perception now, but it is an extra hill for a Country Music station to climb.
While generic national Ford or GM spots may be bought by the numbers, the local dealers have input into what stations their dealership ads go on, and some local advertisers may not even use an agency and make the buying decisions themselves. If everything was just by the numbers, radio stations could replace their sales people with media buying websites similar to the way we order books from Amazon.
The bottom line is that in the NYC area, likely Country Music radio listeners are a smaller minority than the limited number of available commercial FM frequencies can provide a spot for, and as spoken word formats, like all news, or sports talk, move over to the FM band in competitive pairs, the crunch keeping Country out will only get worse.