NEW YORK – CNBC writes that Chick-fil-A's perks program, which entitles participants to free food, private tours and special events, may be the most extensive of its kind. However, most customers don’t even know the loyalty program exists, and it’s only offered in half of the fast-food chain’s 2,000-plus locations. So what gives?

The catch, according to the news source, is that Chick-fil-A’s “by invitation only” loyalty program is a model that means customers can’t actively seek it out. The program began in 2013 to offer for more customized rewards and communication for customers from their local restaurant. The “A-List membership,” notes CNBC, gives customers access to an app where they can learn about Chick-fil-A events and giveaways.

Chick-fil-A's customer base “is among the fast-food industry's most loyal, even when they don't get the red carpet treatment,” writes CNBC. The chain is ranked No. 1 for customer satisfaction in the Limited Service Restaurants industry category, according to the 2015 American Customer Satisfaction Index.

One customer, Henry Kurusz, is not in the A-List program but is a member of Chick-fil-A’s calendar program, which entitles him to free menu items every month. Now, he’s on a mission to become an A-lister. "I need to figure out how to get into the A-List, even if it means buying more chicken…I guess that's what I'll do,” he told CNBC.

Bonnie Riggs of the NPD Group told the news source that the only way for fast-food chains to increase store traffic in the current landscape is to seek loyal customers, noting that people “want to be recognized for their loyalty. Chick-fil-A has very strong brand loyalty to begin with and they're just reinforcing it. When the industry sees the impact of this kind of program, others will try to follow suit and invent a similar program on their own."

When asked if competitors such as McDonald’s and Burger King could mirror the intimacy of Chick-fil-A's community-based rewards, Riggs told CNBC, “That remains to be seen. … Maybe at a local level or if a few franchisees get together."