That's partially because Visa/MC's hold on the market was finally broken up thanks to the antitrust suit of '99. Amex is still a bit more expensive (usually about 1% to 1.5% more in some cases), so some merchants may be reluctant to accept it. (The one that drives me nuts the most is those Racetrac gas stations.. although, they were cash only until just a few years ago so I guess I can't complain too much... ok, yeah I can..)