The fast-food giant contributes $76 billion to the economy and employs more than 1 million total workers.

The fast-casual chain has brought in a former culinary executive from Papa Johns and a marketer from Subway.

The fast-casual grilled, bone-in chicken chain hasn't had a chicken sandwich for years, even when everyone else launched one. But it's testing one now.

Preliminary fourth-quarter results indicate improvements in same-store sales and traffic, though the brand has a long way to go. Expect a year of big menu news ahead.