McDonald's, Starbucks targeted by rival fast-food chain's takeover

Every coffee lover knows about the decades-long competition between Dunkin' Donuts and Starbucks, and no matter if they are a fan of either, everyone seems to have their preference. 

Although Dunkin' was founded in 1950, nearly 21 years before Starbucks, the Seattle-based company quickly took over the coffee market, becoming the world's largest coffee shop chain in the U.S. and leaving its senior competitor in the dust.