[runako]

#1 - Yes, I have used it that way before.

#2 - However, our business accepted AmEx from the beginning.

#3 - Europeans are also anecdotally much more unlikely to carry Amex than even other cards.

#4 - My generalization comes from directly communicating with our European customers over 10 years. Their concern was not "I would like to pay with $CARD_WE_DONT_SUPPORT" but instead "I do not have access to any credit card."