Getty Images

The secret is out that “secret” menus at major fast food chains are not remotely secret. So why do restaurants bother at all?

It’s not too hard to get in on a secret at restaurant and coffee shop franchises around the country. Secret menu items—which aren’t listed on order boards, but are readily available to those who ask—are regularly rounded up by the likes of The Daily Meal, Ranker, and Secret Menuholic. McDonald’s, Starbucks, Taco Bell, Jamba Juice, KFC, Denny’s, Five Guys, and White Castle are just a few of the big-name restaurant chains with secret menu items available. A recent issue of Mad Magazine parodied the fast food secret menu craze—the mock items included the Chicken McFlurry at McDonald’s and Colonel’s Cheesy Discharge at KF—which can be read as some indication the trend has been overplayed.

A few well-known chains, including In-N-Out Burger and Panera Bread, even list (not so) “secret” or “hidden” menu items on company websites. That would seem to defeat the purpose. Last summer, when Panera alerted the media about some new hidden menu items, FoodBeast joked that the company had “no idea how secret menus work.”

But perhaps Panera knows better, and is working idea of a “secret menu” to maximum efficiency. As the FoodBeast post notes, there’s a “singular thrill” that occurs when requesting something off the secret menu and getting a “knowing smirk” in return from the restaurant staffer taking your order. Even if the secret menu isn’t really secret, customers can feel like they’re in-the-know and in on something special by ordering items that the clueless masses don’t know are possibilities. It’s this exciting feeling and slow-spreading buzz that can help a restaurant build a cult following among diners.

(MORE: Colorado’s Pot Shops Say They’ll Be Sold Out Any Day Now)

Yet there’s another reason why restaurants are increasingly employing secret menus—and why they don’t really want them to be all that secret. The St. Louis Post-Dispatch summed up why hidden menu items like six low-carb, high-protein options introduced a year ago have become a bigger part of Panera Bread’s business plan:

Executives said the hidden menu isn’t just a marketing gimmick. Rather, they said it’s more off-the-menu because it takes more investment, marketing and risk to introduce and promote new menu items. And they figured these items would appeal to a niche audience.

Restaurant chains are always spicing up menus (sometimes literally) with limited-time offers like the Shamrock Shake and the Pretzel Bacon Cheeseburger. But such LTOs, as the industry calls them, require a lot of time and money devoted to marketing them, so that customers know about them and might even be inclined to order them.

Panera and perhaps others are instead taking a low-risk, low-investment approach to new menu items, by introducing them only on a “secret” menu basis. If such items fail to generate a following, no problem: The company hasn’t spent much money promoting them. Nothing may be gained, but very little has been lost.

(MORE: To Spice Things Up, Fast Food Is Spicing Things Up)

On the other hand, secret menu items can generate buzz and strong customer followings, either quickly or over time. They could even become so popular that the company decides to place them on the official menu. In fact, that’s what Panera Bread just did, adding two “hidden menu” items—the Power Chicken Hummus Bowl and the Power Breakfast Egg white Bowl—to its regular menu. For a limited time only, of course. The LTO is supposed to be officially available through mid-February. After that, it’ll be off the official menu, but should still be able to be ordered by customers who know about the no-so hidden menu.