Walmart pies are suddenly flying off shelves and selling on eBay for $40

Walmart is suddenly facing a widespread shortage of sweet potato pies. 

The $3.48 pies starting flying off shelves last weekend and now they are sold out in many stores and selling on Ebay for as much as $40, NPR reports. 

But when the pies - which were created with singer and cookbook author Patti LaBelle - first debuted in September, no one paid much attention to them. 

So why the sudden frenzy?

Walmart can thank James Wright, a man who posted a musical tribute to the pies on Facebook a week ago.

The video went massively viral, racking up more than 9 million view on Facebook and 2 million views on YouTube in the last six days.

In the three-minute spot, Wright unwraps the pie and breaks into song as he consumes it. He addresses LaBelle and claims you "turn into Patti" when you eat the pies. 

Walmart is now scrambling to make more sweet potato pies.

"We are working very hard with our supplier to try and produce more product," Kerry Robinson, vice president for bakery and deli at Walmart, told NPR. "We're in the process of securing another 2 million pounds of sweet potatoes."

Watch Wright's full review. (Warning: The video includes profanity):