It's a shame that the so called "majors" ignore Southwest. I think that SW scare's the hell out of the big boys.

Slowly but surely, they're adding longer haul flights. They're profitable and any city they go into they immediately drive down the fares. For short hauls, they can't be beat. US used to charge $600 full fare on a vintage 1970 prop plane for the 300 mile trip from BWI to ALB. SW's full fare will be under $150, and you get jet service, too! (See also, PVD, MHT, HFD, etc.)

I guess they figure if they ignore the enemy, they'll go away.