It feels like there’s a Starbucks on every corner, but is there, really? I may spot five green-clad coffee shops on the way to work each morning, but Starbucks doesn’t often flaunt their massive reach. There’s no placemat with maps of every location, à la Big Boy—once you’re big enough, there’s really no good that will come from reminding people just how big you really are.
But University of Washington PhD candidate James Davenport wanted an answer. So he scraped the location of nearly every corporate-owned Starbucks location (in other words, everything but those tiny Starbucks inside grocery stores) from a food review website, then plotted the 8,000 U.S. locations he found onto a map of the country, adding a bit of spatial analytics to the mix.
The first image is a Delaunay triangulation, or a series of unique, non-overlapping triangles connecting Starbucks locations to their nearest peers. This render, unto itself, looks neat, like some dystopian United States in which our territories are decided by coffee proximity. But ultimately, it doesn’t tell us a whole lot.
The next image is a bit more revealing. It’s a Voronoi diagram, which connects the centers of each triangle you saw in the first image. What results is essentially a map of service regions for each Starbucks location. And interestingly enough, when you begin measuring all these vertices, you learn that the farthest expanse between any two Starbucks is a mere 140 miles.
Finally, by applying 2010 census information on population density to this map, Davenport could analyze just how many people were within the reach of any given Starbucks location. His finding was pretty incredible: More than 80% of the U.S. population, or a whopping 250,000,000 people, lives within 20 miles of a Starbucks. And over 30% of the U.S. population lives within a mile of one.
"The end result is that Starbucks does an extremely good job of providing coffee for the U.S.," Davenport says, euphemistically. "One reader from Twitter remarked, rather brilliantly, that if Starbucks had Wi-Fi reception that covered 5 miles, more than half the U.S. would have free Wi-Fi!"
We have to say, that’s not such a bad idea. You may not dig their oft-burnt coffee, but everyone loves free Wi-Fi.