Air France/KLM
has a no-show clause in its terms & conditions. This is important for passengers who have a ticket with a number of flight segments. Take for example a ticket Brussels-Amsterdam-New York-Amsterdam-Brussels. It shows that Belgian travelers flying KLM need to change planes in Amsterdam, which is inconvenient to many passengers. If they fly a Belgian carrier they have a non-stop flight without a plane change. Therefore, KLM offers Belgian customers a lower fare than Dutch flyers to compensate for the inconvenience.
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has a no-show clause in its terms & conditions. This is important for passengers who have a ticket with a number of flight segments. Take for example a ticket Brussels-Amsterdam-New York-Amsterdam-Brussels. It shows that Belgian travelers flying KLM need to change planes in Amsterdam, which is inconvenient to many passengers. If they fly a Belgian carrier they have a non-stop flight without a plane change. Therefore, KLM offers Belgian customers a lower fare than Dutch flyers to compensate for the inconvenience.
KLM Royal Dutch Airlines
The closer to the departure date you book a flight, the higher the fare. But this is not always true. If you book long before the flight's departure the fare will be relatively high. In many cases the optimal time to book is 3 weeks out.
A judge in Germany ruled on December 10, 2018 that 
Everybody wants to know what the best time is to buy your ticket. 
The cheapest time to book flights for Thanksgiving travel is 31-90 days out, and 21-30 days out for Christmas. Travelers who booked during these windows in 2017 saved an average of 10% on holiday fares according to 
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