Qantas mistakenly sold first-class tickets for bargain prices. Here's why it made sense for the airline not to honour the deal in full

Australia's largest airline, Qantas, recently put a deal on its website offering heavily discounted first-class tickets for return flights between Australia and the US. Customers alert and lucky enough to capitalise found themselves paying 85% less than the usual first-class fare, which is upwards of A$20,000 (Pound 10,300).

The problem? The offer was a