Ticket Prices 101

Felix Salmon is a big fan of variable pricing:

The masters of variable pricing, of course, are the airlines, and while people are often resentful that they paid five times more for their ticket than the person sitting next to them did, the fact is that they would be much more resentful if they regularly tried to buy air tickets and found that all the flights were sold out. And conversely, of course, the airlines would lose even more money if they regularly wound up flying half-empty planes. Without variable pricing, one or the other would certainly happen.