I never really read the tips before, but I have been reading some of them now and here is what I think:

Tips and tricks are one thing, but some of the tricks seem more like ways to rip people off. When you cost someone else money because you lied, that is really nothing but stealing. Something like: purposely causing your bag to be lost so the airline will deliver it to you...that is theft; maybe no law defines it as so, but it is wrong and unethical.

So I say..try to get that great seat or free upgrade, or whatever else you can get, so long as you don't lie and swindle and especially don't lie and swindle when it will cost someone more money.

I hope everyone agrees with me!