I think one thing that nobody has mentioned is experience in the game.I started playing late in the last age, and I was one of those miserable $1 undercutters everybody hates.After my experience last RL month, and some time to reflect on my "game", I've changed the way I do business. I still won't leave a route I'm on, but I'm much less aggressive about running 100% capacity and maximizing each routes profit.It appears (to me) that I spend less time chiseling for $500 on a flight. I enjoy my time here more, and I hope that my new method enhances other's playing time.What I'm trying to say is that you can't do anything about undercutters any more than Delta can with Southwest, so either accept that as a fact of life, change your business model, or utilize Cornfields rule.