They are paying WELL above cost of living for the position.
I think the recruiting for these locations needs to be targeted based on a demographic profile. Fresh grads will take anything, unless they are highly recruited due to some stand-out factor like school, side-project.
Experienced people are another story. Here's what sold me on the Ozarks vs. offers in Austin, San Fran, etc:
QUALITY OF LIFE QUALITY OF LIFE QUALITY OF LIFE. I'm a married guy with two kids. I've done the densely populated urban area thing in DC. Walk to work, take the train anywhere, live in a high-rise. Guess what? There are a lot of folks my age doing the same thing in our industry, and they are probably getting sick of it like I am. But I don't want to live in a suburb and fight traffic to get to work. This is where you can come in. Big yard, house, short commute.
These folks made a point of selling a country-living lifestyle with a 10 minute drive to the office (and very flexible telecommuting options). A lot of people want nothing to do with that lifestyle, but the people who do will gravitate towards it.
Another issue you have is the dual-income family. My wife is a full-time mom, so for us this issue didn't exist. Perhaps the affordability of an area allows this for those who want this and don't currently have it. A lot of moms AND dads I know would love to be a stay at home parent if they could. Flyover country allows for this if you pay well above cost of living.
Since I'll be getting a similar salary when I move, I'll be able to save way more for one day starting my own business.....
These are all selling points, and you should highlight them in your ads. It's not about an ad where 99% of the people who see it think "ok, cool." It's about an ad where 3% of the people who see it go "Oh my fucking god I want to do that."