Milk is not a loss leader: they aren’t losing money on it to get you to spend elsewhere.
It’s profitable for supermarkets.
(They definitely do manipulate milk prices to get consumers to shop with them rather than competitors, and sometimes they artificially lower the prices. But they don’t ever do this at their own expense. They do it by forcing farmers to supply below the true cost of production. Because dairy farmers can’t just sell some of their milk. Essentially as soon as a dairy farmer can’t get a buyer for the totality of their product they are out of business. It’s remarkably precarious. So most are pressured into selling below cost for long periods of time.)
Supermarkets might be using it to get customers deeper into the store but milk is also heavy, awkward, refrigerated, and shorter shelf life, which means they are always going to put it closest to the back of the store.
It’s profitable for supermarkets.
(They definitely do manipulate milk prices to get consumers to shop with them rather than competitors, and sometimes they artificially lower the prices. But they don’t ever do this at their own expense. They do it by forcing farmers to supply below the true cost of production. Because dairy farmers can’t just sell some of their milk. Essentially as soon as a dairy farmer can’t get a buyer for the totality of their product they are out of business. It’s remarkably precarious. So most are pressured into selling below cost for long periods of time.)
Supermarkets might be using it to get customers deeper into the store but milk is also heavy, awkward, refrigerated, and shorter shelf life, which means they are always going to put it closest to the back of the store.