Discount codes don't stack. If you have 60% off discount, they can't also use a "free shipping" coupon since Only one discount at a time can apply to a single order at the Amazon site.

Normally, one discount code is only applied for one offer. However, If the users put a vast of items in their cart, it is easy to use one coupon code to purchase items. It depends on Amazon's policy, you can contact Amazon via mail for your reference.

It depends! Normally, the percentage that you can save with that Amazon Coupon will be shown right on the page, so you can see if it is applied sitewide or not. However, once you are not sure, try it right on their's products you want to buy.

Most Big Discount Events of the year witnessed a vast number of coupons from Amazon released. Especially, on federal holidays such as New Year’s Sale, Thanksgiving, Christmas... or on other important days such as Valentine’s Day, Easter, and Father’s Day..., customers also can buy at Amazon with numerous coupons.

Our advice for you to use Amazon Coupon effectively is to choose the right day.
Like thousands of other consumers, the time of promotion is when they choose to
shop at Amazon, so take advantage of coupons released on those days to save.