Mildly Infuriating

It depends on exactly what the store is doing.

If the store is representing the extra charge as a donation to a specific charity, generally, the customer can deduct that.

If it's far more vague, like, "Give $10 to help poor kids in Africa" the ultimate destination for the funds could be the company's own ledgers, which it would then use for its own charitable activities and collect the tax deduction, as long as they "help poor kids in Africa."

And some stores are just lying. CVS, for instance, was sued as part of a class action suit when, after the company pledges $10 million to the American Diabetes Association, then collected money from customers to fund that pledge.

It is a net loss if you donate your own money, in this situation Company isn't donating from its own revenue. It is donating customers money.

If I donated 1000$ and claimed tax deductible it would be a net loss. But if I asked everyone for donations, raised 1000$, donated that and claimed tax deductible that wouldn't be a net loss.

Even if it is revenue, it is still a net loss. All it does is reduce taxable income, which is still makes the donation a net loss. For anyone not aware, the current federal US corporate income tax rate is 21%. So if a company gives 100 dollars to charity, they only save 21 dollars in taxes, so they are still down roughly 79 dollars, depending on the state taxes of where they are incorporated.

I think it’s more just a PR thing to make you feel good about that company while using your own money.

Yep, even without any direct financial benefit there is certainly a reason to engage in such behavior. The store gets you to associate it with the charity campaign and they'll make hay over the amount of donations they helped collect and their partnership with the charity. Drives for employee donations can also be used in a similar manner.

That’s not how tax write offs work

Jerry: So we're gonna make the Post Office pay for my new stereo now?

Kramer: It's a write-off for them.

Jerry: How is it a write-off?

Kramer: They just write it off.

Jerry: Write it off what?

Kramer: Jerry, all these big companies, they write off everything.

Jerry: You don't even know what a write-off is.

Kramer: Do you?

Jerry: No, I don't.

Kramer: But they do. And they're the ones writing it off.

Puppies do not recognize your silly imaginary borders and will commit zoomies across any such lines.

I intended on writing this comment yesterday but jerboa timed out on me. It's a common misconception and I understand how it gets spread, but I wish there was better knowledge and education of how taxes worked in general. Would make it easier for the average person to spot the ways companies do evade taxes, too.