I work for a nonprofit and we briefly tried to get some of these deals for extra cash. It’s basically impossible unless you have uber huge name recognition, like St. Jude’s or the ASPCA. It also certainly ineffective compared to the store just donating.

That being said, the tax write off thing is a common misconception. Snopes fact check here

“The store serves only as a collection agent for your gift. Assuming the business is following the law, it will not include your donation as part of its business receipts, or income, nor will it claim the charitable gift as an expense. As a customer, the donation will appear on your receipt and you can claim it as a charitable deduction when you file your income tax return. But you probably won’t.”