How Kirkland Quietly Became Costco's Most Powerful Moat

When investors think of Costco Wholesale (NASDAQ: COST), they usually focus on its membership model. After all, annual membership fees generate billions of dollars in recurring income and help anchor the company's profitability.

But another piece of Costco's strategy deserves just as much attention. Over the years, the company has quietly built one of the most powerful private-label brands in retail: Kirkland Signature.

What started as a simple store brand has evolved into a strategic asset that strengthens Costco's pricing power, deepens customer loyalty, and reinforces the company's competitive moat.

Image source: Getty Images.

A private label operating on a global scale

Private-label brands are common in retail. Most supermarkets and big-box chains offer their own alternatives to national brands. But Kirkland operates on a completely different scale.

In fiscal year 2025, ended Aug. 31, 2025, Kirkland generated $90 billion in annual sales across categories ranging from groceries and household goods to clothing and electronics. With group-wide merchandise sales of $270 billion, the brand accounts for roughly a quarter to a third of Costco's total sales.

That makes Kirkland larger than many well-known global consumer brands.

Yet, unlike most private labels, Kirkland doesn't position itself as a budget substitute. Instead, Costco aims for something more ambitious: products that match or exceed the quality of leading brands while still offering better value.

That positioning has helped Kirkland become a trusted name among Costco's members.

Trust that reinforces Costco's value proposition

Costco's reputation for value rests on a simple promise: Offer high-quality products at consistently low prices. Kirkland plays a crucial role in delivering that promise.

Many Kirkland products are manufactured in partnership with well-known suppliers. In some cases, the same producers behind premium national brands help make Kirkland products, though the branding remains exclusive to Costco.

This approach allows Costco to maintain quality while keeping prices competitive. Over time, shoppers begin to trust the Kirkland label itself rather than relying solely on national brands. That trust creates a powerful behavioral shift. Instead of comparing products every time they shop, many Costco members simply reach for the Kirkland version by default.

For Costco, that kind of customer loyalty is extremely valuable. It strengthens the connection between members and retailers, reinforcing the broader membership ecosystem.

A quiet source of negotiating leverage

Kirkland also gives Costco an important advantage in its relationships with suppliers.

Retailers typically depend heavily on national brands to attract customers. That dependence can limit their bargaining power when negotiating prices.

Costco's position is different. Because Kirkland is a credible alternative in many categories, suppliers know the retailer has options. If a branded supplier pushes pricing too aggressively, Costco can expand Kirkland's presence in that category. That possibility alone often helps keep negotiations balanced.

The result is stronger purchasing leverage, which allows Costco to maintain its reputation for competitive pricing while protecting margins.

Supporting Costco's long-term moat

Kirkland's importance ultimately goes beyond individual product categories. The brand strengthens several elements of Costco's broader business model.

First, it reinforces Costco's value proposition. When customers believe they can consistently find high-quality products at lower prices, they are more likely to renew their memberships and consolidate spending at the warehouse club.

Second, it helps Costco maintain its disciplined pricing strategy. Private-label products typically carry higher margins than national brands, which gives Costco flexibility to keep overall prices low.

Finally, Kirkland enhances Costco's competitive moat. The brand is exclusive to Costco warehouses, which means customers can't easily find the same products elsewhere. That exclusivity encourages members to keep coming back.

What does it mean for investors?

Costco's membership model often gets the spotlight, but Kirkland Signature may be just as important to the company's long-term success.

By combining scale, quality, and value, Kirkland strengthens customer loyalty while improving Costco's negotiating position with suppliers. Over time, that dynamic reinforces the company's pricing advantage and helps protect its competitive moat.

For long-term investors, the lesson is simple: Costco's success isn't built on a single idea. It's the result of multiple reinforcing advantages -- and Kirkland has quietly become one of the most powerful among them.

Lawrence Nga has no position in any of the stocks mentioned. The Motley Fool has positions in and recommends Costco Wholesale. The Motley Fool has a disclosure policy.