Why is Dunkin' Donuts so popular?
Dunkin Donuts is a coffee and donut franchise with particularly high concentration in the Northeast United States, which is colloquially referred to as New England. Although the quality of the coffee is mediocre and the donuts tend to taste like plastic, Dunkin' Donuts (now re-branded as Dunkin') carries a special place in the heart of many New Englanders. 

Perhaps it's the the fact that you are rarely more than 10 miles away from a Dunkin' franchise at any given time, or perhaps it is their blatant obsession with New England professional sports teams. Either way, Dunkin' has established itself as a household name and weekday staple for many coffee drinkers in the frigid Northeast.
Porque é que o Dunkin' Donuts é tão popular?
A Dunkin' Donuts é uma franquia de café e donuts com uma concentração particularmente alta no Nordeste dos Estados Unidos, que é coloquialmente referido como Nova Inglaterra. Embora a qualidade do café seja medíocre e os donuts tendem a ter um sabor de plástico, a Dunkin' Donuts (agora rebatizada como Dunkin') ocupa um lugar especial no coração de muitos habitantes de Nova Inglaterra.