Wal-Mart and Costco have adopted a version of the one-gallon milk jug designed with efficiency in mind. The boxier containers stack better, eliminating the need for milk crates and conserving space in trucks and on refrigerated store shelves:
> The company estimates this kind of shipping has cut labor by half and water use by 60 to 70 percent. More gallons fit on a truck and in Sam’s Club coolers, and no empty crates need to be picked up, reducing trips to each Sam’s Club store to two a week, from five — a big fuel savings. Also, Sam’s Club can now store 224 gallons of milk in its coolers, in the same space that used to hold 80.