[_delirium]

Afaik they're mostly accepted in Europe via their partnership with the payment processing network of Diner's Club (vs. directly seeing a "Discover" sign). Diner's Club is moderately widespread but only in certain market segments, like restaurants and higher-end stores. Not many European ecommerce shops will take Discover or Diner's Club, not even big ones like Amazon [1].

[1] http://www.amazon.co.uk/gp/help/customer/display.html?nodeId... or http://www.amazon.de/gp/help/customer/display.html?nodeId=50...

[justincormack]

Diner's club is not used much here, it is occasionally accepted, along with the Japanese cards.