Operations

Shake Shack tops loyalty study as burger chains battle for repeat customers

Photo: Shake Shack

September 15, 2026

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Shake Shack has the most loyal customer base among the nation's top burger chains, according to a study, from advertising platform Simpli.fi, offering fast casual operators a data-backed look at what it takes to keep guests coming back.

The report, titled "Whose Cheeseburger Is It?," is the first in Simpli.fi's ongoing "Loyalty in the Real World" series and was timed to National Cheeseburger Day, which falls Thursday. Researchers tracked anonymized mobile location data from hundreds of thousands of visitors to the top 20 U.S. burger-focused quick-service and fast-casual chains across 20 metro markets over an eight-week period, then classified customers as either loyalists — those who visited only one brand — or samplers, who patronized two or more.

Shake Shack posted a 99% loyalty rate, meaning just 1% of its customers were seen at a competing burger chain during the study window. Wendy's, Smashburger, Sonic and Steak 'n Shake rounded out the top five.

Menu differentiation

For fast casual operators, Shake Shack's showing points to a broader lesson about menu differentiation. The report found that brands with signature items lacking a close analog elsewhere in the category — such as Wendy's Frosty — tend to hold onto customers more effectively, since diners have fewer reasons to look elsewhere for that specific craving.

That dynamic matters beyond burgers. As fast casual brands compete not just with each other but increasingly with value-driven casual dining chains, a defensible, hard-to-replicate menu item may do more for retention than price promotions alone.

The study also found McDonald's, despite a comparatively modest 60% loyalty rate, shares the most customer overlap with every other brand in the study, positioning the chain as the top competitor across the category and a magnet for cross-shoppers.

Whataburger's results illustrate a risk tied to rapid growth: as the chain has expanded into new markets, it has seen a rise in cross-shopping, posting the second-highest rate of samplers among brands in the study, at 52%. That's a cautionary data point for fast casual chains eyeing aggressive unit growth, where new markets can mean starting from scratch on customer loyalty.

Overall, the study found 61% of burger visitors were loyal to a single brand, while the remaining 39% — representing a share of the roughly 17 million daily burger purchases nationwide, per Circana — remain up for grabs.

How to build loyalty

Simpli.fi recommends several strategies for operators looking to build loyalty, including:

Using first-party data to target existing customers separately from acquisition campaigns.
Geofencing competitor locations to identify and win over switchers.
Centralizing brand assets so local franchisees can run localized campaigns quickly.
Tracking real-time foot traffic and revenue attribution to gauge which tactics are actually driving visits.

Want to hear more about Shake Shake's strategy?

During the Fast Casual Executive Summit, Shake Shack Chief Information and Technology Officer Justin Mennen will discuss the brand's approach to building its first loyalty platform with a focus on strengthening guest relationships and enabling more personalized communication. He'll also share how Shake Shack is thinking about the role of technology in supporting its long-term growth and enhancing the guest experience.