Airline reservations systems are kind of fascinating, because they were some of the first really complex computer systems, and a lot of those crusty old bits are still chugging along fifty odd years later, with newer and newer piles of code layered on top like a demented tower of jenga.

http://thecodist.com/article/how_flight_reservations_work_pa...

http://thecodist.com/article/how_much_is_that_seat_by_the_wi...

The customer expectations are much lower when shopping for a plane ticket. A painfully long experience is actually expected.

Friction is absent when buying anything from Amazon (because of webperf, UX, etc) so customer expectations standard is way higher. If something goes wrong on Target, Mediamarkt or Carrefour website, the sale is gone and off the customer goes to Amazon.

As a similar example, in France the main way to buy a train ticket was through the railway website, whose UX was poor (as were travel agencies). A small team went at it and built a competing booking website (Captaine Train) whose sole promise was a quick and easy to book a train ticket. They instantly removed the above mentioned friction and became a huge competitor almost overnight.