McDonald's is once again promoting a "farewell tour" for the McRib sandwich.

The seasonal offering, which since its introduction in 1981 has periodically disappeared from the fast food giant's menu, is making one more appearance at McDonald's locations nationwide.

The sandwich will be available starting October 31, and McDonald's has released promotional materials encouraging customers to "enjoy our famous pork sandwich as if it's your last!"

Indeed, the burger chain is hoping that love for the sandwich — which includes a McRib pork patty, bun, barbecue sauce, pickles and onions — will be strong enough to get customers to pay for limited-edition McRib merch, which it will sell on its website during the McRib's "final" run.

"Like any true farewell tour, we're hoping this isn't a 'goodbye' but a 'see you later.,'" McDonald's says in its press release. "Because as our McRib stans have experienced time and time again: you never know when — or if — the McRib is coming back."

It's a strategy that's designed to create a sense of urgency for customers, according to Vanderbilt University marketing professor Kelly Goldsmith.

"McDonald's is leaning hard on the scarcity marketing tactics right now," Goldsmith says. "We see it with the McRib, we see it with their adult Happy Meals which had limited-edition toys. McDonald's is putting scarcity marketing everywhere they possibly can."

Part of the reasoning behind McDonald's recent approach to limited-edition promotions — last year it teamed up with K-pop superstars BTS as part of its Famous Orders campaign — is to create excitement for the brand among a younger audience.

"They're a very iconic American brand, but they're kind of dusty," Goldsmith says. "The scarcity marketing tactics are a way that allows McDonald's to be playful and to stay engaged with their consumers, but also be true to a lot of what makes that brand their brand."

"If you look at the adult Happy Meals, the toys are limited edition and are being resold on eBay for 10x markups. The McRib merch will probably also be limited edition and then get resold at a huge markup," she adds.

"McDonald's doesn't make any money off the eBay secondary market, but the word of mouth is keeping the brand current and getting it into your house in new and different ways."

While McDonald's says that it's possible the McRib will enter its fast food graveyard along with the McPizza, Chicken Selects and Snack Wraps, Goldsmith believes it's more likely than not that the McRib will make a comeback at some point.

"I mean, [consumers] lost it for eight years, right? This is a real threat," she says. "But will it come back? I would guess yes."

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