There are many behind-the-scenes secrets that keep Trader Joe's running, from its Morse code-like bell system to its relationships to brand-name manufacturers. Even some of the less-user-friendly aspects of the chain grocery store are there by design. As Food & Wine reports, the reason many of your favorite Trader Joe's products go out of stock so quickly has to with its unique ordering system.

In a recent Reddit AMA ("ask me anything"), a Trader Joe's employee was asked about to explain why many of the store's best items can't seem to stay on the shelves. Unlike other supermarkets, Trader Joe's avoids ordering more products than it can sell. The employee wrote:

"[...] we order in a system called 'truck to shelf,' which is what it sounds like. We don’t want to order too much. Sometimes we end up with too little. But for us, that’s better, because it’s less waste. It helps keep prices down."

That's a big departure from standard industry practices. Supermarkets end up tossing nearly a third of the food in their inventories. The Trader Joe's policy is not only better for the environment, but it's better for their bottom line. By only ordering what they know they can sell, stores can offer products at the lowest prices possible.

Other items are intentionally pulled from shelves to drive demand. Trader Joe's sells many limited and seasonal products, like pumpkin spice rolls and turkey and stuffing potato chips. Instead of offering sales or advertising what it sells, Trader Joe's plays with supply and demand to get people excited to buy certain products.

Keeping prices low and making certain items feel special are just some of the ways Trader Joe's has grown into a cult supermarket brand. Here are some more facts about the chain and its unusual business model.

[h/t Food & Wine]