The only places I've found that refuse AMEX are very small mom and pop operations. And of those, many don't accept cards of any type: cash only.
Costco?
[Edit] -- And I've frequented several independent coffee shops that are cashless.
Fair enough, it's probably not as common as I think and is more of a reputation.
Costco?
[Edit] -- And I've frequented several independent coffee shops that are cashless.