There is a geographic component. Outside the U.S. acceptance of Discover is not nearly as universal as in the U.S. So much so that in the letter that accompanied the new Discover debit cards they sent out, they had something to the effect of “maybe you should bring a backup card” if you were planning on using it internationally.
xp84|1 month ago
They should make a card with a second chip on the other end (that will only be approved if used abroad) so that you can still use an ATM on a trip.