KANSAS CITY — Last fall, Burger King unveiled the Big King sandwich, featuring two beef patties, a thousand island dressing-style sauce, lettuce, cheese, pickles and onions on a three-part sesame seed bun.

Sound familiar?

So closely resembling rival McDonald’s signature Big Mac in name and composition, the Big King begs the question: Is the sandwich a shameless rip-off or a smart play?

Burger King differentiates its version of the drive-thru double-decker by its beef, which is flame-broiled, not grilled. The chain also challenged McDonald’s last year with another menu mimic: the BBQ Rib sandwich, a McRib lookalike at a lower price point.

But the Mac attack may backfire for Burger King.

When competitors copy iconic brands, the original product receives new attention and, potentially, stronger sales.

At least that’s the hope of the Hershey Co., which last month was defending its Reese’s Peanut Butter Cups on the debut of Nestle’s Butterfinger peanut butter cup, which has a peanut butter filling mixed with crunchy pieces in a milk chocolate shell.

“I think anything that brings people to the category is great,” said J.P. Bilbrey, president and chief executive officer of Hershey, during a Jan. 30 earnings call. “Reese’s defines, largely, the sweet and salty segment. Usually when you have a variant of a parent brand, it never becomes as large as the parent. And so, while I’m sure that it’s a great product and they will do well, we will make sure that we are fighting for our space.”

Hershey’s latest introduction, however, may also suggest product plagiarism. Launched in mid-January, Hershey’s Spreads includes a creamy chocolate hazelnut flavor that some are calling a knockoff of Nutella. Hershey said it entered the category to compete in the fastest growing sub-segment of chocolate-based spreads, led by the runaway growth of Ferrero’s brand.

Nutella was one of the top-growing items on menus last year, according to market research firm Datassential, with a compound annual growth rate of 46% from 2009 to 2013. Unsurprisingly, the J.M. Smucker Co. craved a bite of the craze and launched its own line of hazelnut spreads in 2012.

More than ever it seems imitation has become a new form of innovation, as food makers set out to dethrone the dominant player in a given category. Others simply want a small taste of the success. After the hit hybrid pastry known as the Cronut debuted last May, its creator, New York bakery owner Dominique Ansel, trademarked the name as a spate of croissant-donut copycats emerged in bakeries and donut shops across the country, called Doughssants, Fauxnuts, Cray-nuts and Kronut Krullers. Even bigger players hopped in the ring, including Dunkin’ Donuts, which offered a similar product in South Korea called New York Pie Donut, and Crumbs Bake Shop, which dubbed its version the Crumbnut.

While McDonald’s has not commented on its fast-food foe’s launch, a description of the Big Mac on the chain’s web site says enough: “There is only one.”