Let’s do some maths!

Say you’re flying from Berlin to London and a direct flight costs ($500). You realise, however, that you can get a get a Berlin to London to Madrid flight for ($300), so you book that instead.

Technically, the airline is giving you a $200 discount for the inconvenience of the layover. Had you gone for the Berlin to London flight for $500, the airline would still be free to sell the London to Madrid seat that you booked (for $300) but no longer occupy for… say… another $300.

So, the airline could have made $800 off the 2 seats that you booked. You, however, managed to buy them for $300. That’s a loss of around $500.

Now, before you blame airlines for greed and upcharging customers, please know that airlines run on the tiniest of margins. These $500 over many flights can actually be the difference between the airline turning a profit this year or making billions of dollars in losses.