Personally, I think using the landing fees at Denver as an excuse not to provide service is a crock, to put it lightly. Even if they are higher than in other locations, other airlines still have to pay these higher rates as well. It might drive up Southwest''s average CASM, but they should also be able to charge a slightly higher fare than normal to make up the difference. Even if the "landing fees and other rentals" at a place like DIA were double (meaning even higher than a 100% hike over other places, as other rentals are included into this line item in the quarterly report), the average difference to Southwest would be about $5.50 each way per passenger based on average trip length and current load factors. That may be a significant % of their profit (or all of it) if they charge to get the same RPM as other locations, but you can easily charge the $5.50 extra without destroying your business. The alternative for those customers would include driving to Colorado Springs, which would cost them far more than $5.50 each way.