I actually dont find too much of a problem with that in the States. Most places accept amex and if they dont, I tend to stay away from those places naturally. I've gotten into a couple of discussion with some owners of the stores that dont accept amex and their excuse is that amex charges 1% more than visa/mastercard. But I'd rather avoid those stores (or at least pull out another card from my arsenal in my wallet) instead of having to pay for them.

At least I can find some relief that Neiman Marcus and Saks prefer amex