How Aldi can have such low prices:

• minimize staff – a full-size grocery store has about six staff on duty
• groceries are shelved in their boxes – they just more or less cut the fronts off
• large and easy to find bar codes for scanning
• a refundable quarter deposit to get a shopping cart? in my humble opinion maybe this meant something decades ago but it is a gimmick now, other than maybe in locations where shopping cart theft is common. Even then, a quarter is not much of a financial deterrent – perhaps a small psychological one.
• They “stock only about 2,000 product lines” compared to say a Walmart which stocks over 100,000.

The article says they bring prices for all grocery stores within a 10-mile radius down by about 1%. Competitive markets are not completely debunked, it turns out…

I would add my own experience that in spite of all this, an Aldi is not a miserable place to shop, compared to say, a Wal-Mart or a traditional grocery store. Shoppers know they are putting up with minor inconveniences in exchange for rock-bottom prices. But the minor inconveniences (like time in line) are certainly no worse than a Wal-Mart, and probably not worse than a traditional grocery store. The lines look long, but they really do move them through quickly. They make the customer bring their own bags or boxes, and do their own bagging away from the checkout counter – but this is the trend at the major chains too. At least, making the customer do the work, I would argue minus the thought given to efficient spatial layout that gets a customer out of the checkout person’s and next customers way while they are bagging. I wouldn’t say the anecdotal, small-sample-size-collected-with-my-own-eyes employee happiness/grumpiness index is up to Trader Joe’s standard (do they hand out free MDMA to employees of something?), but again probably better than Walmart and no worse than a traditional grocery store. The big bar codes and better checkout layouts seem easy for the major chains to copy if they want to, while some of the other approaches would mean big changes in their business models and target customers (Aldi has a notable lack of grab-and-go sushi, for example).