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@Seek_Kolinahr and @bob_ nailed it.
Also, sometime back there was a big to-do about egregious price fixing of US breakfast cereals. I guess it was (and probably still is) the highest % profit margin item in a supermarket. There was a big backlash for a while. I still second guess buying cereal.
Anything shelved next to a loss-leader (like a 12-pack of Coke at cost – itself an egregious high profit margin item, if at retail) is because the ancillary items right next to them are high profit margin items, like chips.
Arizona Iced Tea caused a fuss in the industry because they printed on their 23oz cans $.99 so that markets and convenience stores were losing face for selling them at almost twice the cost. I’m a big fan of Arizona Iced Tea for that one.
I wonder how profitable auto dealerships are too. Those rat bastards.