Beyond breakfast, pork is not typically a big item at fast-food restaurants. But Burger King's limited-time menu offering of pork ribs is changing that dynamic, says As long as they can keep the ribs coming, that is.

Some Burger King Holdings Inc. restaurants are running short of ribs, according to a report in The Wall Street Journal. In fact, the chain might run out of its entire rib order, supplied by Tyson Foods Inc., before the promotion is due to end later this month, the Journal says.

"The U.S. consumer has really enjoyed this product and purchased it beyond our expectations. That's causing us to run out a bit early," the Journal quoted John Schaufelberger, Burger King's senior vice president of global product marketing and innovation, as saying.

Good news for Burger King, who has at times been at odds with its franchisees over the company's desire to push value-menu cheeseburgers and other items that are not extremely profitable for the restaurant operators. It also may be good news for quick-service restaurant companies overall, if customers prove willing to spend on more expensive items.

Marketing tests before the product roll-out had indicated that customers were likely to buy the smaller, less expensive versions of the rib order, costing $1.99 to $2.99. But on a national scale, customers proved to like the larger six- and eight-piece servings, costing $5.69 and $7.19.