The proof is in the foam: Specialty drinks like lattes, which tend to be the most expensive, are posting the strongest growth in the coffee beverage category, Riggs said. And although the coffee market is crowded, with everyone from Starbucks and Dunkin’ Donuts to smaller chains like Intelligentsia competing for consumers’ dollars, Riggs said coffee sellers are finding ways to expand the market instead of fighting over the same group of java-loving customers.That’s helped by a focus on breakfast, which has seen growth while lunch and dinner slow, and afternoon snack time, when more people are justifying a cappuccino when they take a break from work, Riggs said.