Walmart gets to advertise about how Walmart raised a million dollars for children's hospitals, which sounds a lot like Walmart donated money to children's hospitals.

The actual donation really does go to the charity and Walmart doesn't get to claim it on taxes. The dodginess is in the marketing, improving their reputation at your expense. Walmart takes the credit for customer donations.

the legitimate promotions of this sort; and walmart, as big and as greedy as they are, are still most certainly doing this on the 'up and up', the donations are tracked separately and separate from the revenue stream. it just gets passed-through to the charity. no tax deduction shenanigans involved. walmart already has other 'legal' loopholes and accounting tricks to use to lower their tax burden, they don't have to do something blatantly obvious and easy to track that isn't nearly as 'effective' at it.

Walmart can not claim your donations as a charitable donation on your behalf.

Regardless if a person does or doesn't claim the charitable donation, Walmart never is able to anyway.

There may be other shady aspects about an organization you are donating to and Walmart may be able to make claims on their costs associated with facilitating the donation (for example the costs to set up and maintain the transaction process) but they never ever ever are able to claim your donation, doing so would simply be fraud and there are better ways to cook books than claiming 10 million individual charitable donations on behalf of 10 million people.

The customer is the one that gets the donation receipt to claim on their taxes.