Milk sits at the far wall of nearly every supermarket, and eggs and bread rarely sit near the door. The arrangement reflects two separate constraints that happen to point the same direction.
High-frequency items anchor the route
Stores know which items bring shoppers in most often, and placing those items far from the entrance guarantees a walk past other categories.
Exposure matters because a large share of supermarket purchases are decided in the aisle rather than written on a list beforehand.
The layout is therefore a routing decision, using the items a shopper is certain to want as fixed points along a path.
Refrigeration equipment lives at the perimeter
Refrigerated cases require compressors, condensers and drainage, and consolidating that machinery in back-of-house space is far cheaper than distributing it through a floor.
Walk-in coolers behind the dairy wall also allow restocking from the rear, so shelves are filled without carts crossing the sales floor.
That engineering reality means perishables would sit at the perimeter even without any merchandising theory, and the two rationales reinforce each other.
Produce at the entrance sets an impression
Most stores open into produce, where color, misting and arrangement communicate freshness before a shopper has evaluated anything else.
Produce also carries relatively high margins on prepared and packaged items placed alongside the loose goods.
The decompression zone just inside the door is generally kept low-density, since shoppers adjusting from the parking lot do not register merchandise placed there.
Shelf position within an aisle is allocated
Within an aisle, eye-level shelves are the most valuable, and placement is negotiated between retailer and supplier through category planning.
Store brands are commonly positioned adjacent to the leading national brand so the price comparison is unavoidable.
End caps at the aisle ends receive disproportionate traffic and are used for promotions, which is why an end cap price is not necessarily a lower price.
Layout changes are deliberate and disruptive
Periodic resets rearrange sections, breaking the habitual paths regular shoppers have built and forcing them to look at shelves again.
Resets also let a store update space allocation as categories grow or shrink, which is a genuine operational need rather than only a traffic tactic.
The disruption is understood and accepted, because a shopper searching for a relocated item passes more merchandise than one walking a memorized route.