The chicken in Popeye's sandwich crunches audibly when you bite in, with all those nooks and crannies on the surface shattering into a thousand delicious pieces.

No wonder Popeyes ran out of its new chicken sandwich.

An analyst at KeyBanc Capital Markets estimates the fast-food chicken restaurant sold about 1,000 chicken sandwiches per store a day. Sandwich sales also accounted for about 30% of Popeyes sales in the time it was available while store traffic doubled, the analyst said, citing proprietary tracking data. For this reason, the firm is bullish on the parent company, Restaurant Brands International, and raised its earnings estimates.

The sales boom got its spark after a Twitter feud with Chick-fil-A in August led consumers to try the new sandwich. The chicken sandwich's massive popularity also sent ripples through the fast-food industry as Popeyes same-store sales skyrocketed.

"Unbeknownst to [parent Restaurant Brands International] at the time, the launch of a new chicken sandwich at Popeye's and subsequent twitter debate would be a viral sensation that would disrupt the fast food industry and likely shape the outcome of 3Q19 results for some of the category's largest players," analyst Eric Gonzalez said in a note.