Are tall non-fat frappacinos the new Big Mac?

Think there’s already a Starbucks on every corner? Just wait. The fast-growing chain plans to nearly triple in size and some see it growing even bigger, one day topping hamburger giant McDonald’s Corp. as the largest fast-food brand in the world.

The chain has set a goal of 30,000 units, half in the United States, but last month the company’s chairman suggested the target is too low, leading to speculation on what is the limit for the chain—and when Starbucks will set a new goal.

Starbucks is credited with rapidly transforming coffee from a 50-cent staple to a $3 indulgence with its chain of comfortable cafes, where customers often hang out with their laptops or newspapers for hours. The chain has been criticized for driving independent coffee shops out of business while aiming to give its own stores a local feel by sponsoring community events and steering clear of national advertising.