In the restaurant industry, there isn’t much room at the top, and sticking around in this business means building a following of dedicated fans. A good name, menu or location isn’t always enough—in order to succeed, brands need loyalty from customers. In the difficult casual-dining sector—where chains are surrounded by disruptive actors like Blue Apron meal prep, UberEATS food delivery, and the fast casual industry—that fact is now truer than ever.

Last year, Foursquare released its first Quick Service Restaurant Loyalty Index, a measure of consumer patterns based on a group of monitored consumers across the U.S. This month, the same concept was applied to casual dining to produce the Casual Dining Loyalty Index using the same methodology.

Foursquare measured loyalty based on four tenets.

Frequency measures the average annual visits per customer to each brand. Penetration is the percentage of category visitors who visited that brand within a year. Share of wallet indicates the median share of each customer’s total casual dining visits to a particular chain over a year. Finally, the “Fanaticism Threshold” shows the number of visits within a year required for a user to be within the top single percent of users who visit a particular chain.

Based on a combination of those factors, check out the casual dining chains in the U.S. with the most loyal customers.

While the last few years have been rough overall for the wing chain, Buffalo Wild Wings has remained popular among core fans of the brand. To credit might be the Blazin’ Rewards loyalty program, which rewards repeat customers for dining at the restaurant and was rolled out in all BWW locations this year. It went national in June and, at the time, already had more than 1.6 million guests onboard, and over 21 percent of sales were tied to those loyalty member checks. Now under the Inspire Brands umbrella following the $2.9 billlion sale to Arby’s Restaurant Group, changes should be coming. What are they exactly? Only time will tell.

Old Chicago is relatively small compared to many of the large, national chains on the list, but anything lacking in size is made up for in loyalty. The chain has tapped into the local and craft beer trends that are popular among consumers, which has bolstered loyalty to the chain despite lower levels of brand recognition in some areas of the country.

Denny’s has focused on fulfilling the expectations of a brand that’s now more than 60 years old by blazing forward unabashedly. Already known for a quick-witted social media presence, the diner chain has focused on making improvements across the board, from food quality to building design and everywhere in between. Check out the brand’s latest Star Wars campaign. Also, here’s how it plans to revitalize its image for a younger audience and propel into the future. In Q4, Denny’s grew its same-store sales 2.2 percent versus the prior-year period and closed out the year with a 1.1 percent increase, which marked seven straight years of positive system same-store sale

Applebee’s is another brand that has maintained loyalty in spite of adversity. The Dine Brands Global imprint closed more than 100 locations in 2017, but customers remain loyal to their neighborhood grill. The brand has focused on rebranding current locations, deepening bonds with existing customers, and most essentially, reaching out to younger generations and making a lasting impression. Applebee’s domestic same-store sales rose 1.3 percent in the fourth quarter versus the prior-year period, showing that some of its recent changes might be taking hold. Read more about the brand’s climb back to the top of the casual-dining mountain here.

IHOP is another Dine Brands concept that has faced declining comps over the last couple years, but continues to focus on rebranding and building loyalty with current customers. And when it comes to pancakes, does anyone have a more loyal following from a national perspective? The restaurant has poured time and money into menu research and development to further appeal to millennial customers, and how fanatics get their pancakes is changing, too, as IHOP considers delivery strategies. IHOP’s domestic comps dropped 0.4 percent in Q4. In its 60th year, the chain is also launching a fresh campaign called, fittingly enough, “Pancakes, Pancakes, Pancakes.” Read more about it here, as well as how IHOP plans to repackage six decades of brand sentiment for new and old audiences.

Cracker Barrel is another chain looking to appeal to younger demographics, but its supporters are as loyal as any. Don’t believe them? Ask Ray and Wilma Yoder, the couple that’s traveling the country, eating at every Cracker Barrel one by one. For those who haven’t yet been convinced as thoroughly as the Yoder family, Cracker Barrel recently launched an ad campaign for its new Southern Bowls item aimed specifically at millennials. In Q4, although foot traffic was down 0.9 percent compared to this quarter in 2017, comparable restaurant sales grew 1.1 percent. Retail sales bulged an additional half percent. The chain, comprised of nearly 650 units in 45 states, received a boost from the Tax Cuts and Jobs Act of 2017 in the form of a $1.63 per share benefit, which pushed GAAP diluted earnings per share all the way to $3.79.

Bill Miller Bar-B-Q is the smallest brand on the list, but fans at the nearly 70 locations across Texas sure love their pork and brisket to come from Bill Miller. The brand isn’t afraid to keep the menu fresh and fun—this month, certain locations debuted chorizo tacos to a great level of success, showing that menu innovations are a great way to drum up loyalty and excitement.

Hooters is unique on the list because part of the brand’s pitch is the waitresses, not just the food. But the brand sticks with fans for a plethora of reasons, as evidenced by its continued presence on the loyalty index. Recently the brand partnered with Fox Searchlight Pictures to launch a limited-release Snozzberry Sauce in honor of “Super Troopers 2.” Hooters finished out 2017 having opened eight new corporate-owned locations and 17 franchise-owned locations. This year, Hooters plans to open at least 14 more corporate locations in the U.S., and an additional 20 franchise locations globally.

Mellow Mushroom might be the prime example of having a menu that breeds loyalty. While there are a million and one pizza shops in any given town, Mellow Mushroom’s menu is unique enough that customers are able to differentiate between a quality pizza and a quicker, lesser quality pie. While the price point on a pizza is higher at Mellow Mushroom, the quality is strong enough that customers will remain loyal and fork over the extra dough.

Beef ‘O’ Brady’s is another indication of the power of a loyalty rewards program. The Team Rewards program at Beef ‘O’ Brady’s encourages customers to sign up and immediately start gathering points for meals eaten at the franchise. These quickly add up to rewards deals, adding on top of promotional meals every month and just for signing up. By giving back through the rewards program, Beef ‘O’ Brady’s ultimately is bringing money back into its doors. In August, CapitalSpring acquired a majority stake in FSC Franchising Co. LLC, the franchisor of Beef ‘O’ Brady’s and The Brass Tap. Beef ‘O’ Brady’s currently operates 172 locations in 23 states. There are 50 Brass Taps in 22 states. Read more about what changes could be in store for the legacy chain.

From among the restaurants ranked most loyal, Foursquare highlighted a handful of qualities that might boost loyalty based on trends from this year. They suggested focusing on bar drinks, developing trendy menus, and combining forces with smart mergers.

Here are the other chains, in order, that filled out the top 50 in loyalty rankings:

• Ninety Nine Restaurant
• Hard Rock
• Twin Peaks
• Miller’s Ale House
• Uno Pizzeria & Grill
• Chili’s Grill & Bar
• TGI Friday’s
• California Pizza Kitchen
• BJ’s Restaurant and Brewhouse
• Outback Steakhouse
• Islands Restaurant
• Houlihan’s
• Red Robin Gourmet Burgers
• Yard House
• Bar Louie
• Bertucci’s
• The Cheesecake Factory
• Texas Roadhouse
• On The Border Mexican Grill & Cantina
• Dave & Buster’s
• O’Charley’s Restaurant + Bar
• Olive Garden
• P.F. Chang’s
• Bonefish Grill
• Ruby Tuesday
• Carrabba’s
• Kona Grill
• LongHorn Steakhouse
• J. Alexander’s Restaurant
• Seasons 52
• Benihana
• Famous Dave’s Bar-B-Que
• Logan’s Roadhouse
• Saltgrass Steak House
• Maggiano’s
• Red Lobster
• Cheddar’s Scratch Kitchen
• Mimi’s Cafe
• Brio Tuscan Grille
• Joe’s Crab Shack