Reply #1: The folks over at UAL "yield-management"

[BlueCollar]

are trying to fill that airplane before it leaves.

Airplane seats are a perishable commodity. Once the plane takes off the seat has no value so every attempt is made to fill the seats.

Let's say that the flight costs $10,000.00 to operate. (Fuel/landing fees/crew labor costs/Ground support labor costs etc.), and let's pretend that there are exactly 100 seats on the plane.

Theoretically, if UAL sold every seat for $100.00 they'd break even...however if they only sold 99 seats they'd lose money. As a result, they're constantly adjusting fares in order to maximise the number of seats sold.

If the flight has a historical seat-sold rate of 90 seats, the boys over at yield calculate the fare at over $100.00 to make up the difference. Anything sold over 90 seats is profit...but if they only sell 67 seats they take a loss on that flight on that day.

Clear as mud?

Airline ticket pricing is one of the most dynamic and complex business processes I have ever witnessed.

Hope that helps.