You might expect people to be keen to purchase pie at this time of year, as our peak national pie-eating holiday approaches. Yet a pie fever is currently gripping the country: celebrity pie fever, as Walmart is suddenly unable to keep its new Patti LaBelle-branded sweet potato pie on the shelves.

Fortune magazine spoke to the Walmart executive responsible for the pie fever, Kinna Thomas, senior buyer for cakes and pies. Wanting to improve the chain’s desserts, she began the process of sending her family sweet potato pie recipe to its mass-baking suppliers to find the best pie.

It turns out that R&B star LaBelle is famous for her own sweet potato pie, and some of her flourishes were added to the Walmart version before it went into mass production.

The pie has been for sale nationwide since spring, but you probably haven’t noticed or heard about it. Then a combination of two things happened: fall began, Thanksgiving approached, and a much lesser-known singer than Patti LaBelle posted a video review on YouTube that became a viral sensation, turning the pie itself into a viral sensation.

Now the pies are mostly sold out, with people even flipping them on eBay.

The sweet potato pie project did exactly what it was supposed to for Walmart: got the word out that they have some high-quality bakery items. Maybe even high enough quality to draw middle- and upper-middle-class people who wouldn’t normally shop at Walmart into their stores.

How Patti LaBelle’s Sweet Potato Pie Craze Is Reinventing Walmart’s Bakery [Fortune]

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