Plain and simple...they charge because "a la carte" is the current trend.
Low end hotels=free wifi, high end hotels=$10+/day
How to increase revenue without alientaing a huge number of frequent fliers? Exempt them from fees, and charge all the rest.
As for weight restrictions...extra fuel is loaded for alternate destinations....if u land at primary, u have xxx lbs of extra fuel, making the landing too heavy...due to poor weather at destination.
Overhead space not being used? That is a crock...seems someone was talkin out his butt.
Selling cargo space? happened before, will happen again..nothing has changed there.
It is simply another form of a la carte pricing to increase revenues...nothing more.
DL (I believe it was them) conducted a study that the average bag costs about $15 to transport in incrimental costs (beyond initial facilitie cost which at a hub is HUGE for a sorter system) in terms of labor and fuel. $15 for 1st bag is on par with their study, $25 for 2nd bag seems to make a profit. Simple economics.