No less a literary publishing lion than Roger Straus once said, "I don't publish books, I publish authors." And wouldn't every literary house wish it could say the same. But for shifting editors, vanishing imprints and authors hungry for the highest dollar from the highest bidder, it might be a rule of thumb.

Alas, today, it is rare that one house, in partnership with an author, with patience and forethought, builds a first-timer into a spectacular success. But north of the border, in Toronto, Harlequin, North America's largest publisher of romantic fiction, has turned it into an art form. Like any art, it is half intuition, half business acumen and all about relationships.

Romance dominates the American fiction market, accounting for 40% of all sales. Nora Roberts remains queen of the category, with nearly 12 million copies sold last year; but her numbers are slipping. Coming on strong is Debbie Macomber, a former housewife from Washington state, apple-cheeked and gifted with boundless energy. A quarter-century ago, Macomber was a harried mother with a manual typewriter, a supportive husband and a burning desire to tell stories. She was a fan of romance fiction and she tried her hand.

Her first effort, Starlight, was published as a numbered title (#128) in the Silhouette Special Edition series at Harlequin, a series of more than a thousand titles by dozens of authors. But it was a start. After a half-dozen more such entries, Macomber, in 1988, got her own series, Navy, which ran to five titles. And then another series—Manning, then another, Orchard Valley. Craig Swinwood, the executive v-p of retail marketing at Harlequin, explains the cumulative effect. "Here was a young writer whose books, in mass market paperbacks, were going out there in huge numbers—150,000 copies, two or three titles a year. Over time, with that exposure, an author can build a sizable audience, certainly more than a traditional young novelist could do with a standalone first book, a standalone second book, et cetera."

In fact, at the time, Harlequin did not even think to publish a standalone book. "We didn't have a single-title program," Swinwood explains. "All our books were series. They went into outlets on a regular basis like magazines, but in those huge numbers. For an author who is finding a good reception, demand and name recognition build."

In 1994, Harlequin, tired of seeing top authors like LaVyrle Spencer and Catherine Coulter decamp for publishers who could publish single titles effectively—often in hardcover—started Mira, a mixed format single title program.

In Swinwood's words, "For certain of our authors, for whom a large audience has been built, we can bet on a single title—and in hardcover. We have found that a loyal fan base will follow."

Building authors and leveraging a loyal readership into hardcover sales is what Harlequin has done for many of its authors over the years, and Debbie Macomber is the poster girl for the Harlequin magic. With 150 titles and counting under her belt, she is a bona fide superstar whose numbers continue to grow—"at a 25%—30% clip a year," says Swinwood. Last year her new books sold 2.8 million copies, bringing her total in print to more than 60 million.