Originally Posted by radonc1

Basically, at the volumes you are talking about, the answer to your first question is probably yes.
You are talking about a huge amount of money going in essence to a single type of purchase. At best, Amex will deny you any points or SUB's that you may earn since their T&C's specifically exclude GC purchases. And Amex will know what you are buying.

I presume that you would be using the Amazon GCs to fund an Amazon account in order to purchase items on Amazon. Anyone who is doing $25K/mo in business with Amazon will certainly be able to set up an credit account which can be paid just about any way you wish. I have no doubt that Amex would happy to have you pay a $25K Amazon bill with their card and collect the swipe fee.

What may be more questionable is whether Amazon would be willing to have you pay their monthly bill with an Amex credit card.