What makes a book sell?

That, in these advance-inflated times, is the $640,000 question. If only publishers knew the exact right cocktail mix of product, publicity, timing and luck, they'd be a lot drunker and a lot richer than they are.

This past week, a book called Perfect Madness has burst onto the scene. It was the subject of a front-page New York Times Book Review (mixed, but lengthy); it hogged the cover of Newsweek; and it turned up in countless other papers and on TV shows pretty immediately after it appeared on February 17. And while, as every publisher can tell you, great ink does not necessarily great sales create, journalist Judith Warner's book—about how American women doom themselves to failure because they believe in fairy tales about ideal motherhood—has so far performed solidly. According to Nielsen BookScan, which is thought to account for about 70% of total sales, the Riverhead book sold over 1,000 copies in its first (partial) week, which was pre—all-that-publicity. Riverhead has gone back to press three times and now has 45,000 copies in print. On March 5, Perfect Madness will debut at #35 on the New York Times extended nonfiction bestsellers list.

Why this book and why now? Not that the book isn't worthy; it is. It raises interesting questions and clearly touches a nerve among the childbearing. But so have other books on similar topics in recent years. Remember, for example, Miramax's Creating a Life: Professional Women and the Quest for Children by Sylvia Ann Hewlett? It too got lots of media attention and cover stories, but it was also famously outed in the New York Times for selling poorly. Then there was The 7 Stages of Motherhood by former Parents magazine editor Ann Pleshette Murphy, which came—and went—from Knopf last fall. And last year, on almost exactly the same February date, Free Press published The Mommy Myth, a narrative by Susan Douglas and Meredith Michaels exploring many of the same issues. That book, according to BookScan, has sold nearly 12,000 in hardcover, probably far fewer than Madness will sell, even if Riverhead gets 50% returns. (The paperback of The Mommy Myth was just released; perhaps because of its closeness in theme to Warner's book, it has sold an impressive 1,300-ish copies in paperback in its first two weeks.)

So what gives? Could it be that author Warner, knowingly or not, has tapped into the popularity of politically themed books, as her take on the motherhood myth is critical of government's withdrawal from childcare, health care and women's issues? (The Mommy Myth tended to blame corporate, not governmental, America.) Or that, by choosing to focus on upper-middle-class mothers, her narrative skews sharply toward highly educated, urban women in "blue states" who are only too happy to blame the right-winging of the country for their plight. In other words, Warner's book preaches to the choir—a choir that not so coincidentally buys books.

Apparently, too, Francophilia is back. Like another bestselling "women's book"—Knopf's Why French Women Don't Get Fat by Mireille Guiliano—Perfect Madness compares the American system with the French one, and finds our own wanting. But who knew that "Vive la France!" would go over in a culture that two years ago was eating freedom fries and burying a charming style book called Entre Nous: A Woman's Guide to Finding her Inner French Girl? That St. Martin's book was on a short list for excerpt in at least one women's magazine in 2003, when editors ultimately decided it would be inappropriate to admit we admired the French joie de vivre.

While it's possible, I guess, that Riverhead, like Knopf this time, was prescient in realizing that times have changed, I can't help thinking they were more lucky than smart—or at least that, if they were thinking of anything, it was that the affluent book-buying public would respond more to personal narrative than prescriptive ideas. That's where the prescience comes in: maybe Cindy Spiegel, the Riverhead co-head (and mother) who bought the book, suspected that at least some of us have had enough of the pronouncements of Drs. Phil and Atkins, and that we'd respond better to a more psychological, holistic approach to life's issues.

In these South Beach Diet, Supernanny times, that's a courageous idea—and one I have a feeling that Basic Books is watching closely. That house has its own counterintuitive advice book coming this May. It's called The Last Self Help Book You'll Ever Need. And here's the subtitle: Repress Your Anger, Think Negatively, Be a Good Blamer and Throttle Your Inner Child.