> What's really going to matter is how it's executed. If someone bids $100 to keep a seat empty and the flight is empty, do they still get charged the $100? Or is it only when there's a limited number of empty seats and more people that will pay to have an empty seat next to them.

For sure they will, and probably that's what they are after. Think of it like this, when you pay for an economy seat and get 2 adjacent seats for free because the plane is half empty you're basically winning the lottery since many travellers are randomly assigned. The airline will monetise on this from now on by opening up the bids.

It's very interesting also to see to what degree prices will go up since this would create some scarcity. The airline is probably happier to accommodate as few passengers as possible due to the extra passenger overhead (check-in, bags, service) though the math is quite hard considering upsales and all.

All in all, I have always been fascinated about the complex problems the airline industry is solving and this only adds more to it. Would really like to see the software implementing all this.