Originally Posted by
cbn42
I doubt very many people would stop shopping there. I find it very difficult to believe that people are more loyal to a credit card issuer than to a merchant. Normally, people decide where to shop and then think about how to pay, not vice versa.
We Flyertalkers, of course, might be different.

I hear you, but I do avoid places that do not take AMEX. Granted they're not big merchants like Costco but, just like in Costco's case, I can easily buy what I need elsewhere. There's nothing I buy at Costco that they carry exclusively and that I must have.
What I find fascinating about this credit card exclusivity agreement is that most merchants try to offer their customers as many payment options as possible in order to facilitate sales. Costco is exactly the opposite: they're perfectly fine turning away customers who don't carry a specific type of CC.