The world's favorite card. More than 57 million cards in circulation and growing! Around US $ 123 billion was spent last year through American Express Cards and it is poised to be the world's No. 1 card in the near future. In a regressive US economy last year, the total amount spent on American Express cards rose by 4 percent. American Express cards are especially popular in the U.S., Canada, Europe and Asia and are used widely in the retail and everyday spend categories.