Panera swimsuits are selling like hotcakes. What’s next?

In June, the quick-serve chain introduced its latest fashion line, “Swim Soups: the You Pick 2 Collection,” inspired by its “You Pick 2” menu combos. The line includes eight mix-and-match pieces based on popular menu items (from grilled cheese to its strawberry poppy seed salad).

Panera seems to have the recipe for what people want. An earlier swimsuit launch, in 2021, sold out. And in February, it quickly sold out of the “BAGuette,” a long green purse embossed with the letter P, designed to promote its new toasted baguette sandwiches. (Panera cannily dropped the BAGuette days before Fashion Week.)

Panera isn’t walking the runway alone. “Fast-casual” merchandise, often in the forms of limited-time co-branded apparel and accessory lines, is becoming standard among quick-serve restaurant chains including Taco Bell, Chipotle and Sweetgreen SG . Some chains are entering several co-branded collabs a year. Among others, product lines have evolved from seasonal sensations into year-round staples.

Panera, for example, in May debuted The Panera Shop featuring menu-based “Carb Couture.”

Should retailers worry?

Quick-serve food chains are finding protein in their fast merchandising ventures. For starters, the “inside joke” cleverness of these goods can appeal to consumers who don’t even eat the food. And it generates social media buzz that’s essentially free advertising.

Following are examples of other QSR merchandising strategies that boost brand awareness.

These product launches can result in unexpected demand, which can lead to unanticipated problems, as McDonald’s learned with its adult Happy Meals. But they also present partnership opportunities for retailers, which know a lot about meeting demand.

A quick sampler of these opportunities:

1. Show them your privates. Retailers that make private-label goods, which is most, can offer to manufacture merchandise for QSR chains (and help distribute and sell limited product releases).
2. Give points for loyalty. Retailers and QSRs can join forces on loyalty program initiatives. For example, a customers can buy a QSR-branded frozen meal at the supermarket and earn points toward the next QSR purchase.
3. Catch a buzz. Retailers can ride the social media waves of QSR chains by posting their own alternate or complementary products. Think of a scarf/napkin to tuck into (or tie onto) Panera’s BAGuette.
4. Share the dish. Retailers can enter into limited data-sharing agreements to help QSRs “see” how their customers spend their time and money outside of their chains. The insights can instruct more relevant messaging and product launches.
5. Lastly, retail marketers should follow these QSR chains, literally – visit their restaurants, order from their menus, read their social posts. This will reveal how much consumers will pay to stand apart from the crowd.

Because, when it comes down to it, that’s what everyone craves: a “special order” that gets attention. QSRs are just putting it on their menus.