In 1978, the Airline Deregulation Act passed, and the federal government of the United States relinquished control of the cost of fares. Suddenly, US airlines had to compete for their customers. Texas International Airlines took an innovative approach and launched the first ever frequent flyer program.
You go on a flight, and you get abstract frequent flyer miles. You collect enough of these miles, and you can exchange them for a very real, free flight (or upgrades and discounts on whatever). Even if a particular Texas....