ABC's of Couponing: "B" is for BOGO Stacking

This topic dives deep and stores policies may vary; I can’t guarantee your experience will be exactly as outlined when working with Buy One, Get One Free coupons and sales, but at least I can help inform you on how they should work.
Common question:

I’m confused by the BOGO sales when they are matched up with BOGO coupons, how do the items come out free?

Let’s start with the background info on how stores work.  As I explained in my first ABC’s of couponing post, stores get paid the full price of a scanned manufacturer coupon. But if a store has a sale or coupon that it releases, this is called a store coupon.  This coupon doesn’t get reimbursed – it is a form of advertising for the store.
If a store has a BOGO free sale (or store coupon), they are “taking the loss” so to speak on the free item.  If you hand them a manufacturer coupon for a BOGO free item during their BOGO free sale, it doesn’t affect the amount of money the store makes.  Because the manufacturer reimburses them for the coupon.
True BOGO Free Sales:
At most stores, if a sale is buy one get one free, you purchase one and the other is free.  So if you use a BOGO free coupon on top of the sale, both products end up free. The store gets reimbursed for the manufacturer coupon and the transaction is still profitable for the store! Even though you didn’t pay money out of your pocket.

However, not all stores ring up BOGO free store sales (or store coupons) this way.  Some insist that you must pay for one item in order to use your BOGO free coupon. Rather than giving you both items for free, you buy one and then receive two free (one free for the coupon and one free for their sale).
Non-True BOGO Free Sales:
Certain stores have BOGO free sales, but you don’t have to buy 2 to get the sale price.  You purchase one, and it rings up half price.  Some examples of stores that work this way are Publix (except Florida locations, which are true BOGO sales), Bi-Lo, and Harris Teeter to name a few.  If you use a BOGO free coupon with a BOGO free sale at these places, you will pay half price for one item and get the other item free.
Can I use two BOGO Free Manufacturer’s coupons for two items?
No – if you have two BOGO free coupons, you’d have to purchase 4 items to use them both.
Can you use two manufacturer coupons on a buy one get one free store promotion?
Yes!  Even if the store is giving one away for free, you can still use a coupon on it! So if you have two $1 off one item coupons, you could use both of them on a BOGO free sale! You just couldn’t use two BOGO free coupons.
How does using a BOGO free coupon on BOGO half off sale work?
If you purchase two items that are $4, the store would ring up one item as $2.  Then when the cashier scans your BOGO free coupon, it may only take off $2 for the cheaper item you bought.   Other stores will take off the full $4.  It depends on how your cashier rings you up.
Can I use a BOGO free coupon and a $1/1 off product coupon on two products?
This is the most tricky question of them all!  If you have  a BOGO free coupon, but you have another coupon for $1/1 on the same product, can you use the both coupons?  If done on certain coupons, this is called “piggybacking” and is not how the coupons were intended to use.  Now I don’t promote coupon decoding (the practice of using coupons on items they weren’t intended to be used on) so I won’t go into too much detail, but you can tell be the coupons codes whether you can use a BOGO coupon with another coupon or not.  Most of the time you can not – if the number 14 is in the area circled in the barcode below, the coupon is attached to both products. You can’t use another coupon on your purchase for either product.   If the numbers are different, some stores will let you use a BOGO free coupon and a $1/1 product coupon when you buy two items.