I have an idea that's related to (4) - actual last minute flight deals.
You go to the airport you want to travel from, and go to a "last minute" lounge, preferably behind security. Then, every time a flight is about to leave that has empty seats, the seats appear in an auction (available on smartphone devices or via wifi in the lounge) that will last maybe 10 minutes. The winner gets a digital boarding pass and is required to report to the gate within 10 minutes, or the flight is lost. The idea is that almost any revenue from an otherwise empty seat goes directly in the contribution margin.
There are any number of problems, especially getting not-yet-travellers through security, as well as baggage, but the essense of selling a very-soon expiring product is the same.
You go to the airport you want to travel from, and go to a "last minute" lounge, preferably behind security. Then, every time a flight is about to leave that has empty seats, the seats appear in an auction (available on smartphone devices or via wifi in the lounge) that will last maybe 10 minutes. The winner gets a digital boarding pass and is required to report to the gate within 10 minutes, or the flight is lost. The idea is that almost any revenue from an otherwise empty seat goes directly in the contribution margin.
There are any number of problems, especially getting not-yet-travellers through security, as well as baggage, but the essense of selling a very-soon expiring product is the same.