What’s funny about those $4 prescriptions - there was a WallyWorld spokesman on the radio right after the program was announced - and when the host described it as a loss-leader, the spokesman laughed and said - nope - They are still making a good profit at that price.
Let’s not forget that it draws people in to fill their perscriptions and at least 7 out of ten end up buying at least $20 of other items while they are waiting for their prescription to be filled.