Back in the early '80s—when the only "superfreak" the world knew was the one immortalized by Rick James as "a very kinky girl, the kind you don't take home to mother"—Stephen J. Dubner wanted to be a rock star.

Dubner played guitar, piano, and accordion, and in his words, "sang and jumped around a lot" in the Right Profile (a band that drew its name from a Clash song), toured with the Del Fuegos, and was signed to Arista Records by music-business legend Clive Davis in 1986. The band broke up before it could finish its first major-label release, but some samples of their work—along with photos of Dubner and his bandmates posing shirtless and with some superfreaky hairdos—can be found on the website of singer-guitarist Jeffrey Dean Foster.

Twenty years later, Dubner, 46, has finally achieved the stardom he wanted as a young man with his new partner, Steven D. Levitt. Together, Dubner and Levitt sell into the millions. They tour regularly, playing to sold-out crowds. And they court controversy with each release, their latest inspiring at least one critic to accuse the duo of going "way over the line" and "shocking the bourgeoisie."

But Dubner and Levitt don't sing, and the only jumping around they do is from topic to topic, covering everything from drug dealers to sumo wrestlers, terrorists to prostitution. Levitt is a prize-winning economist and professor at the University of Chicago, and Dubner is a former New York Times Magazine editor turned author. Together they wrote Freakononomics, a wildly—one is tempted to say freakishly—successful pop-economics book released in 2005.

This week they released a sequel, SuperFreakonomics, which extends the first book's playful, unconventional examination of the world through the eyes of (to echo their first book's subtitle) a rogue economist. As they begin the book's publicity blitz—on the day of its release their publisher took out a full page ad in the New York Times and both men appeared on Good Morning America; ABC's 20/20 will devote a full hour to the book on Friday—there's little risk of them needing to pose with their shirts off to get attention.

According to a fact sheet provided by Dubner and Levitt's publisher, William Morrow, Freakonomics was on the Times Best Sellers list for 111 weeks and was translated into 34 languages. (A gallery on the book's website shows covers from around the world, many playing off the original's apples-and-oranges radical counterintuition theme, like a banana peeled back to reveal a corn cob from Norway or a pear containing a lightbulb courtesy of some twisted art director from Estonia.) Both men are popular speakers at corporate and educational events. Don Walker, president of the Harry Walker Agency, which represents Dubner and Levitt, as well as Bill Clinton, Dick Cheney, and actual rock stars like Bono, told Portfolio.com, "In 65 years in the business, rarely have we represented anything as successful on the lecture circuit as Freakonomics has become."

It wasn't always so. Talking to Portfolio.com on the eve of the book's release, Dubner recalled profiling Levitt in 2003 when the latter was an up-and-coming economist who "tends to see things differently than the average person," for The Times Magazine in a piece headlined "The Probability That a Real-Estate Agent Is Cheating You (and Other Riddles of Modern Life)."

"I remember telling my wife while I was working on it, I can't imagine anybody's gonna care about this," he said from the office he rents on Central Park West in Manhattan. One person did care: The first phone call Dubner got when the piece came out was from Levitt's mother who thanked him for "treating her boy fair."

Book deals were offered to both men separately, and Levitt and Dubner agreed to collaborate on the suggestion of Dubner's agent, Suzanne Gluck. Critical reception for the book, which appeared in 2005, ranged from rapturous ("If Indiana Jones were an economist, he'd be Steven Levitt. Mr. Dubner is a treasure of the rarest sort; we are fortunate that Mr. Levitt managed to find him," gushed Steven E. Landsburg in the Wall Street Journal) to merely very favorable ("It might appear presumptuous of Steven Levitt to see himself as an all-purpose intellectual detective…but on the evidence of Freakonomics, the presumption is earned," wrote Jim Holt in the Times.) One dissenter was Time's Amanda Ripley, who called Levitt "whip smart," but complained of the book, "There is no unifying theory here, which is a shame."

After the book, the pair started writing a Freakonomics column in The Times Magazine. The paper even began hosting their blog. Suddenly, Freakonomics was more than just a book. It's become something resembling an institution.