IN THE early 1980s, American Airlines, strapped for cash, decided to start selling passes for unlimited first-class travel for life. At the time, the passes cost $250,000 (around $600,000 in today's dollars), with a companion ticket available for an extra $150,000 and discounts for older people. The Los Angeles Timesexplains what happened next:

"We thought originally it would be something that firms would buy for top employees," said Bob Crandall, American's chairman and chief executive from 1985 to 1998. "It soon became apparent that the public was smarter than we were." The unlimited passes were bought mostly by wealthy individuals, including baseball Hall-of-Famer Willie Mays, America's Cup skipper Dennis Conner and computer magnate Michael Dell. Mike Joyce of Chicago bought his in 1994 after winning a $4.25-million settlement after a car accident. In one 25-day span this year, Joyce flew round trip to London 16 times, flights that would retail for more than $125,000. He didn't pay a dime. "I love Rome, I love Sydney, I love Athens," Joyce said by phone from the Admirals Club at John F. Kennedy International Airport in New York. "I love Vegas and Frisco."

In other words, Mr Joyce, who paid around $1m for his airpass, made back one-eighth of its cost in less than a month. If this seems like it was a fantastic deal for people who could afford it, that's because it was. (AA stopped selling the passes regularly in 1994, although it did offer them again in 2004, in the Neiman-Marcus catalogue, for $3m each. None sold.) It was such a good deal for flyers—who also earned airline miles on each flight—that American started regretting it. In 2007, the airline began investigating its passholders, to see if any were taking improper advantage of the programme.

You can click through to the Times piece to find out the outcome of AA's investigation. But there's a lot to learn from this story. It illustrates how having the money to make significant investments when opportunities arise can pay off enormously in the long-run. It demonstrates that savvy consumers really can take advantage of enormous corporations if the corporations make silly mistakes. (What's really shocking is how long American kept this deal going—it took nearly a decade and a half for the airline to realise it was getting the short end of the stick.) And it shows how much some people love to fly. If AA or another airline ever offers this kind of deal for that kind of price again, it's worth considering if you have the resources and expect to live long enough to take advantage of the deal. After all, it's way cheaper than having your own private jet—and you don't have to pay the pilots or the staff.