I cannot recall the last time I encountered an actual business that would not accept any credit card, Amex or any other.
It's things like insurance premiums, HOA fees, utilities, taxes (except federal) and other government services that often do not accept Amex. And non discretionary expenses are our biggest and most consistent expenses. They are designed to be paid by checks I suppose, but I like to use them to meet MSRs.
A SUB chaser's problem. 
I started following this thread and oddly enough, on a trip a few days ago had my AMEX Gold card denied at a cafe in a city in Washington state. 
It was a smaller but older, well-established place. It didn't appear to be run by immigrants, so no connection to that reference upthread. I paid with my Chase Sapphire Reserve Visa Infinite. I got the Gold card last fall and I've had at least two or three places (domestically) refuse to take it in less than a year. That never happens to my Visa/MCs. AMEX may be more widely-accepted than before but Visa/MC are still king, IMO.
@W261w261 wrote:<Probably much of your potential business is "walking around the corner" too.>
I agree with the penny-wise pound foolish argument viz my Audi repair. I've never lost a customer because I don't take Amex. It's the nature of my business that if someone pushed me to do it, I'd make the phone call to set it up. I'm sure it will happen eventually, but right now, with gross revenues of almost 2 mill, I only have 2 customers who charge. At first, I resisted all cards, not for the 2%, but I was scared of the charge back potential.
Why on earth would anyone push you to accept credit cards? It would not be that big a deal to them. They would either pay you with something else, or they would "walk around the corner". You have no idea how many customers or potential customers "walked around the corner". Or how many use you but would have been happier if you accepted credit cards.
