Restrictions
Amazon restricts the following categories from free-shipping promotional offers:
Fulfillment by Amazon (FBA) orders
Books, Music, Video and DVD (BMVD) products
Applying Promotions
All promotion discounts are applied to the original order subtotal. Promotions do not accumulate.
For example, if a buyer receives both a $10.00 discount and a 10% discount on a $100.00 order subtotal, we calculate the total discount as follows:
$10.00 discount: $100.00 - $10.00 = $90.00
10% discount: $100.00 x 10% = $10.00 discount = $90.00
Total discount: $20.00
There are combinability rules that affect how promotions with claim codes are applied. For more information, see Claim Codes and Combinability.