You may love it. You may—not to tip our personal hand or anything—abominate it as the work of a crafty caffeine Satan. Either way, you probably don't know how Starbucks' pumpkin spice latte conquered America's autumnal tastebuds. The tale, told by Allecia Vermillion of our sister magazine Seattle Metropolitan, sheds light on corporate flavor research, the ultimately unknowable voodoo of marketing, and the capricious but incredible power of the American consumer to take something—anything—and make it big. Not just big, but huge: since a small Starbucks team formulated the PSL 11 years ago, the Mermaid has moved 200 million frothy mugs of vaguely pumpkin-like murk.

The result, as we all know this time of year, is a pop cultural fixation inspired by few non-alcoholic drinks. Or, as our colleague Allecia ably reports:

Fans paint tiny Starbucks cups on their nails. They dress their dogs up in latte costumes for Halloween (pug-kin spice latte—get it?). They post online comments like, “Can it be fall now? I am so ready for Pumpkin Spice Latte, pants, warm sweaters & lots of cuddles.” The morning after the first presidential debate of 2012, the nation was talking in nearly equal measures about Obama’s curiously detached performance and a front-page Wall Street Journal article about a temporary shortage of pumpkin spice lattes after an early-season rush.

How big is the PSL? Bigger than the presidency. Read the whole dark, cinnamon-spiked tale.