By having a really low range of inventory and really high turnover of that inventory so they focus on bulk buying only a few items. Walmart sells everything and

By having a really low range of inventory and really high turnover of that inventory so they focus on bulk buying only a few items. Walmart sells everything and there is a cost in supporting being a one stop shop. In Aldi it's typical to have 1 type of smoked back bacon for example while Walmart might have 10 types of smoked back bacon.