While we don't typically think of beverage chains as "fast food," companies that are more known for their drinks actually make up some of the largest fast food chains. As it turns out, the fast food chain that is poised to become the biggest in the world is one that is undoubtedly thought of as a "fast drink" chain.

Starbucks has been growing at a rate faster than both McDonald's and Subway — the top two fast-food chains when it comes to sheer numbers — and while McDonald's has plans to expand, Subway has actually been losing locations. It seems like just a matter of time before Starbucks becomes more ubiquitous than Subway.