Amazon offers Select American Express Membership Rewards Cardholders: Additional Savings 20% Off (Max Discounts $40) on Eligible Purchases when you use at least 1 Membership Rewards Point and follow the instructions below.
Thanks Community Member needgeech for finding this deal.
click on ‘Activate now’ to link your American Express Membership Rewards account to your Amazon account
Add eligible products sold & shipped by Amazon.com to your shopping cart (Promotion can be redeemed in one or more transactions for a total discount of up to $40)
Proceed to checkout and select your American Express Rewards Card as your payment method
Select the amount of Membership Rewards Points you would like to use for the purchase (must use at least 1 MR point)
The discount will automatically apply when you purchase eligible items if you qualify for promotion