It is one of the beer world's biggest mysteries: How did a small brewery at the end of a small industrial park in a small town near Chicago become the best brewery in the world?

Three Floyds Brewing, beneath a water tower in Munster, Ind., has been making the best beers on the planet for four of the past five years -- at least according to the more than 1 million beer reviews logged each year on (In 2008, it slipped to second place.) Of course, as Three Floyds sales manager Lincoln Anderson put it, "That's really cool, but what does it really mean?"

Here's one answer: It means Three Floyds has won over the beer geek elite, the sort of guys who frequent

RateBeer, drive hundreds of miles to snag limited releases and trade rare bottles like baseball cards.

It also means that these beers, when gray-market entrepreneurs fill a van or U-Haul and schlep them to the District of Columbia, for example, sell here for between about $20 and $40 per 22-ounce bottle. And it means that maybe, just maybe, Three Floyds has stumbled upon some sort of secret truth about how the beer world works, a secret that accounts for the cult of Floyd.

That secret sheds light on one of beer's biggest, most enduring trends: the rise of "extreme" beers such as tongue-numbingly hoppy imperial India pale ales and Valvoline-look-alike imperial stouts.

Anderson -- big, bearded and heavily tattooed -- drove me to the brewery and brew pub. On the stereo, he played the Grammy-winning singer-songwriter Gillian Welch. "If that disappoints some beer consumer that I don't listen to Slayer all day and all night, well, sorry," he said.

His unexpected taste in music isn't the only way Three Floyds defies expectations. For one thing, even its milder styles are unusually hoppy. The brewery's flagship beer, Alpha King, is about as full-flavored and citrusy a pale ale as one can find. What's more, these beers are scarce: Three Floyds distributes in only five states.

Then there's the popularity of its Dark Lord imperial stout, a beer so beloved that it has its own annual holiday of sorts, Dark Lord Day, during which the entire year's supply is released at the brewery.

The beers were uniformly excellent -- but the best in the world? They tasted pretty close to similar products from Stone Brewing, AleSmith and any number of other hop worshippers. So what's going on?

A persuasive answer comes from Eric Clemons, a professor at the University of Pennsylvania's Wharton School and an expert on how access to information has transformed the practice of business.

In 2006, Clemons and two co-authors published a journal article about RateBeer that examined how ratings predict sales growth. Beer, Clemons notes, is a highly "differentiable" product: Unlike, say, vodka, it can vary almost infinitely in characteristics from color to alcohol content to flavor and aroma. By analyzing hundreds of thousands of beer reviews, Clemons found that the brewers whose sales grew the most were not just those with high ratings, but those with the biggest gaps between their highest and lowest ratings.

"It is more important to have some customers who love you than a huge number of customers who merely like you," the paper concludes -- even if your beers are so intense that they turn off a lot of potential customers. "Good, solid, likable, average, middle-of-the-range new products that consumers neither love nor hate will not sell."