Interesting. Didn't know that. Does the interchange fee depend on where the card is based or where the purchase is made? Will you potentially screw up someone's cost calculation if you use a US card in Germany?

And yea, then assuming that most folks who buy tickets ex Germany on the German LH site would also pay with such a 0.3% German credit card makes those stupid credit card surcharges even more annoying. We'll nickel-and-dime you ... just because we can!