Stackable coupons often provide the best deals. There are two types of stackable coupons:
Stackable Coupons Compatible with Instant Discounts
Stackable coupons that can be used with the existing instant discounts already available for a product are the first type of stackable coupon. These are more common than the second type. In contrast, some coupons simply can't be used if there are already discounts available. Other coupons reduce the amount of the instant discount after applying the coupon. These are semi-stackable coupons, because although you save more after using the coupon, it is not fully stackable since the amount of the instant discount is reduced.
Stackable Coupons Compatible with Other Coupons
Coupons that can be used in combination with other coupons provide some of the biggest savings available. Because they are such a good deal, coupons that stack with other coupons are rare and don't usually last long. Dell is known for providing both types of stackable coupons, and HP has also been providing some as of late. Lenovo tends to only provide the first type of stackable coupons, although their instant discounts are usually very good.