Bruce Horovitz

USA TODAY

Chicken Fries have taken flight -- again.

Roughly two years after nixing the slower-selling Chicken Fries from its menu, Burger King is responding to ongoing social media pressure and on Monday brought back the fry-shaped chicken pieces that are placed in over-sized, French fry-like containers and sold nine to a carton for $2.89.

For Burger King, it's a three legged marketing stool. One leg is the company's recently-stated new mission to limit new product introductions to those that it strongly believes will have bigger impact. A second leg is its continuing bid to appeal to Millennials with social-media focused campaigns -- which is driver for this one. The third leg is simply making better use of an icon that it already has, but had relegated to the menu dust heap perhaps a bit to hastily.

"Demand for this product is so fanatical that we asked ourselves: Who are we to get in the way of our guests having Chicken Fries?" says Eric Hirschhorn, Burger King's chief marketing officer for North America.

Social media conversation about Chicken Fries continued long after they were removed from the menu in 2012, says Hirschhorn. That reached a crescendo, he says, earlier this year after BuzzFeed posted a story about some foods folks still crave -- but can't get any more. "This ignited a conversation -- and we're responding," Hirschhorn says.

At one point, he says, BK was seeing one tweet every 40 seconds about Chicken Fries. Outside of BK's influence, there also was a Change.org petition to bring them back; several dedicated Facebook pages and some Twitter accounts.

Bringing back old products -- typically, for a limited time -- isn't new. "It's likely a case of bring back a proven menu item at a time when the company could use some excitement," says Sam Oches, editor of the trade publication QSR Magazine.

McDonald's brings back McRibs annually to stir excitement and boost sales. Wendy's recently brought back its Pretzel Bacon Cheeseburger and today even announced the unusual burger is now a permanent menu item. BK officials are being a bit coy on how long Chicken Fries will be sold this go-round. "As long as supplies last," Hirschhorn says.

Most marketing efforts behind the Chicken Fries campaign will be social media-focused. There's a Snapchat campaign. A new Tumblr site for Chicken Fries. And on eBay, BK has created a Chicken Fries "Fan Shop" were folks can purchase anything from T-shirts to bumper stickers to bikinis with the "I support Chicken Fries" logo.

"We have a fanatical base for this product," says Hirschhorn. "Now, they can go buy it in our restaurants."