I hate to say it, but Mesa's hiring strategy must be working if they keep on filling classes (despite having the lowest first year pay in the industry!).
I'm sure the "no interview" policy has something to do with it (of course, desirable bases, new jets, and the promise of a fast upgrade contribute as well).
But, lowering the barrier to admission must contribute quite a bit. Perhaps the other regionals could learn a thing or two from Mesa?