Sex sells, but you don't have to tell the editors of Cosmopolitan that. The venerable women's magazine, which is more than a century old, has gone through a number of changes over the years; these days, women turn to it (in droves, with circulation around 3 million) for tips on fashion, men and, above all else, sex. Which is why the subject matter for the magazine's return to the book business was easy to choose. But with last year's Cosmo Kama Sutra, the magazine has seen its literary experiment pay off more handsomely than expected. The title, released in February 2005, has sold more than 300,000 copies. Now, with a water-friendly sex book called Cosmo's Aqua Kama Sutra (which features moves for the beach, shower and tub) out this month, and three more titles planned through 2007, Cosmo's top editors are feeling confident that they can do as well on the bookshelf as on the newsstand.

While numerous magazines have been lending their name to book spinoffs for years, few work on their titles in the hands-on manner that Cosmo does. Although published through Sterling's Hearst Books division, Cosmo's book projects are launched and handled almost entirely in-house in an effort spearheaded by deputy editor John Searles and editor-in-chief Kate White. The key to the success of the first book, White said, was that it was written and shaped (as all the titles will be) by Cosmo editors and contributors, making it more "on-brand," she said.

Another advantage White and Searles see to keeping the books in the family is that it affords them easier marketing opportunities. After doing an initial editorial spread for the Kama Sutra book when it came out in February, the title was plugged again in December. Both editorial spreads resulted in sales spikes. Aqua, with an 85,000-copy first printing, was featured in the June issue. "We've been able to be our own marketer, which is nice," White said.

White and Searles are hoping to see the magazine release two books annually. Although most of their upcoming books are sex related—Naughty Notes is set for November 2006, Steamy Sex Games for June 2007 and the Big Sex Book (which White describes as a "soup to nuts" guide) for fall 2007—Searles and White said they're looking to cover more general relationship topics in future efforts. For now, the duo is happy to be putting Cosmo's name to good use in bookstores. As White put it: "It's exciting to be at a brand that's mature but still going gangbusters."