Originally Posted by jonnye
... One other issue I forgot to mention in my argument was Utility Companies i.e. your Gas/Water/Telecoms/Banking. I'm not sure what the position in the US is like for paying your bills with your Amex, but in the UK very few Utility companies will accept any type of payment other than Visa/Master or Switch.
It's the same here for utilities. Only Visa, MasterCard, and Discover are accepted...presumably not Amex because of the higher fees.
Only exception is mobile phone companies, all of which take Amex. I charge my T-Mobile bill to my Green card for the double MR points.