AP Photo /Martin Meissner, file
In this July 30, 2002 file photo a man carries two plastic bags in front of an ALDI market in Gelsenkirchen, Germany.
The German company has more than 8,000 stores around the world and is rapidly expanding. It's estimated that 90% of Germans shop at Aldi.
Aldi has developed a huge cult following, with fans online sharing tips and tricks for how to shop there.
Here are a few reasons people love the brand.
1. Low prices
Groceries at Aldi are "shockingly cheaper" than those at Wal-Mart, according to a study by Cheapism. They're also cheaper than those at industry darling Trader Joe's.
About 90% of the products at the grocer are private label. By eliminating the middleman, Aldi can pass the savings on to consumers.
Aldi sticks to private labels and offers fewer items than the typical grocery store, a strategy also used by Costco. While the typical store offers 40,000 items, Aldi offers just 1,400.
Selling fewer items increases sales volume and helps drive discounts.
2. Fast check-out lanes
Aldi's German founders valued efficiency, and it shows in stores.
Produce is packaged together and sold so cashiers don't have to weigh items at checkout.
Even Aldi's private-label packaging is designed for easy scanning with its checkout systems.
This means that customers spend less time waiting at check-out.
ALDI SÜD/Facebook
3. Customer responsibilities
Aldi asks customers to bring bags from home for their groceries. If they want bags, they have to pay a small fee for them.
Customers also pay a quarter deposit to use a shopping cart at Aldi.
"The shopping cart rental system is one of many ALDI efficiencies that enable us to keep our prices so low," the company writes on its website. "By not having to hire someone to police the shopping carts, we are able to pass the savings on to our customers."
Trusting customers with responsibilities makes them feel accomplished after shopping there.
4. Double Guarantee
Aldi vouches for its private label.
If for any reason customers aren't satisfied with one of its in-house products, the retailer will refund his or her money and give them a new product for free.
This increases the likelihood that customers will try a brand they aren't familiar with, and gives the retailer credibility.
5. Organized stores
Aldi is meticulous about the design of its stores.
The brand makes sure that all of its stores have consistent layouts.
This means that customers won't feel confused when they visit a new location.