Starbucks dominates the iced coffee market. Cold drinks account for 75% of its beverage sales.TIMOTHY A. CLARY / Getty Images Starbucks dominates the iced coffee market. Cold drinks account for 75% of its beverage sales. Tim Hortons wants in on this, too. It's expanding its range of specialty cold coffees and eyeing further growth. Cold drinks tend to cost more, but they can also cause headaches for staff. More and more customers are shunning piping-hot cappuccinos in favor of fruity cold drinks and iced coffees at chains like Starbucks and Tim Hortons.Cold drinks account for 75% of Starbucks' beverage sales.Sales of cold espresso beverages were up 13% year-over-year in the quarter to July 2, and cold foam, which can only be added to chilled drinks, is the fastest-growing customization at Starbucks, CEO Laxman Narasimhan told investors last week.