Alaska is big on hiring 'locals', they're not going to bring someone from Chicago to Anchorage to interview, they'd much rather give the spot to someone local who doesn't have to relocate halfway across the country. They can't NOT hire you because of where you currently live (if you've made the effort to get yourself to the interview) but they don't want people who will quit after a month because they suddenly realize Alaska is cold.
I *think* Alaska puts you up (provides lodging) during training. So the $40/day perdiem does not have to pay for housing. I could be wrong on that, and if someone who has actually been through an Alaska interview/training has other info I hope they'll speak up. $40/day is quite generous, when I went through training at Eagle and AA we were not paid ANYTHING. We were put up in a hotel, and meals at the training center were provided, but there was no pay at ALL. We were not even considered employees until the day after graduation from the training program.