Intersting topic.

There were at at least two solutions to the issue of airlines selling last minute seats WITHOUT damaging revenue... (these are examples from Australia)

The first was a 'flexi' ticket. You decided which destination you wanted to go to and got a very cheap fare - however you had to call the day before you were due to fly and the airline would allocate you a seat on ANY of its flights on that route for that day.

So you could be on a 6am, or you could be on a 10pm. So the fares were no good for busines people and protected revenue.

For long-haul domestic flight (back in those days there was only 1 or two non-stops a day between SYD/MEL and Perth!) you called the day before you were due to fly and woul either be allocated a seat on the expected day OR could be allocated a seat the day after. So you were guaranteed to arrive either on the day, or the next day. Again - any flight could be allocated.

Secondly we used to have 'mystery flights' which were sold in bands - starting at $99, then $199 I think.

The passenger would purchase a ticket and then ring the day before travel to see where they were going. The airline had the flexibility to put them on any flight, at any time, to anywhere.

The fares came with a guaranteed amount of time at your destination, which think was 2 or 3 hours.

I think if you paid the higher level you either got to fly farther (so somewhere exciting - but still only for a couple of hours) OR you got a longer amount of time at a short haul destination (5 or 6 hours - enough time to get into the city, have a look around, have a bite to eat and make your way back to the airport).

I believe the tickets were quite popular on weekends, and for people who just waned to experience flying!

I don't know why they stopped the mystery fares. I suppose now with airfares so cheap anyway ($99 was a lot of money 15 years ago!) planes are full enough and the cost of administration must be quite high.