That is because AMEX charges much higher fees. At my dad's shop, it's about 3% while visa/master card is only 1.5%.m (I'm not 100% sure though). Since my dad m

That is because AMEX charges much higher fees. At my dad's shop, it's about 3% while visa/master card is only 1.5%.m (I'm not 100% sure though). Since my dad mostly has high volume purchase (and only one or two a day) the 1.5% can mean a lot. He also says doing business with AMEX is hard (if there was an error) because he gets ridiculously few purchase and they don't consider him valuable enough. And everybody who has a AMEX CC in Europa has a Visa or master card as well.