By 4:30 most mornings, Adriana Trigiani is up and writing. She gets in several hours before turning her attention to another part of her job—talking about her books with reading groups.

Trigiani, the author of novels including Big Stone Gap and the forthcoming Rococo(Random House, June), meets on average with four book groups a week by phone. "I put on my headset and do my laundry. I do everything but the carpet sweeper while talking to them," Trigiani says. The author, who lives in Greenwich Village, occasionally visits local groups and hosts reading clubs from the suburbs who come into the city to have lunch with her. "I consider it part of my job. Five years ago, an author went on tour for two months, if at all. But now I know that this is an ongoing process, year-round," she says. The author works hard—"It's a killer just to answer the emails because you get hundreds"—to keep the members of these clubs as happy and as likely to recommend her books to others as possible. And she's not the only one.

Emboldened by their growing power to turn books into bestsellers—and extend the sales life of titles far beyond that of most bestsellers—reading groups are making demands and transforming the way publishers, booksellers and authors market titles. It's as if the readers most vital to publishers and booksellers—the dedicated book buyer looking for at least one new book a month and hoping to talk about it with a dozen or more friends who will therefore need to buy it too—have unionized, forming little locals around the country and doing a kind of collective bargaining on behalf of their members. They've asked for and received reading group guides, other supplementary material both by and about the author, and, most of all, direct access to writers through book-club tours, in-store appearances and remote visits via e-mail or phone.

The payoff for catering to these requests can be huge. Books groups helped Azar Nafisi's Reading Lolita in Tehran sell more than a million copies, and The Secret Life of Bees, by Sue Monk Kidd, to sell almost four million. The latest example of the power of book group word-of-mouth, The Kite Runnerby Khaled Hosseini, has sold about 1.5 million copies in the year since its paperback publication.

This rise of the book clubs' influence has brought a new era in publishing, marked by a profound change in the way readers interact with professionals in the book industry. A decade ago, before Oprah Winfrey brought the reading group to national attention with the start of her television book club in 1996 and before the Internet became integral to consumers' lives, readers did not usually interact in any meaningful way with the industry. Publishers published books, booksellers sold them, authors promoted them at signings and on media tours, but any sense of who was reading what remained anecdotal at best. Now, with reading groups to suit every literary taste sprouting up, meeting at chain and independent bookstores and in people's homes, and the ubiquity of the Internet and e-mail, these clubs have become a potent network, organized loosely by their shared need for information about the books they are reading and for suggestions on what to read next.

A decade ago, things were different. "People weren't exercising their power as readers," says Jane Glaser, book group coordinator since 1995 for Harry Schwartz Booksellers. Today, many reading group members troll the Internet for information about authors and books in order to plan their selections up to a year in advance. "They could do my job," Glaser says. "It's scary. I have people who know what's coming out on the fall list before I do."

The aggressive readers Glaser describes are a bookseller's dream. Independent bookstores are courting them by sponsoring clubs, while at the same time providing recommendations and ordering books, often at discount, for other groups. Their Web sites offer a virtual companion to these services. Amazon and have also devoted significant Web resources to offering groups information and recommendations.

Even in their most rudimentary form, reading groups can be a powerful tool, boosting a book's sales by eight or a dozen copies every time they select a title. Through the Web, that elusive word-of-mouth hit is amplified to a new level, as book groups are talking to one another, and back to publishers, on bookseller Web sites and sites such as At Schwartz in suburban Mequon, there are three bays devoted to displaying what groups in the area are reading, meaning that the groups' choices reverberate well beyond the clubs themselves. "Book clubs are so strong that when you put it on those shelves people pay attention," Glaser says. "This is another suggestion to them of what is good."

One Schwartz customer, Vicki Marx, a member of the Ski Moms Book Club, says she closely follows those suggestions. "I usually pick my reading from there and most are great books to recommend for my clubs," she said.

The rise of reading groups' importance coincides with the shrinking of space devoted to reviews and other book coverage in many publications, making these clubs all the more crucial to publishers. In fact, in some cases book groups may even pack more influence than the opinions of experts, says Jennifer Hart, associate publisher of HarperPerennial, "It's the most organic way a book becomes popular or well known—from the ground up. Reviews certainly do help get attention," she says. "But I'm going to tell [a friend] what to take on vacation—and that's how bookselling happens."

In exchange for contact with authors and extra services from publishers and booksellers, book group members provide a new kind of direct access to themselves. Publishers now can know who book buyers are—not only conceptually as a group of readers who like women's fiction or biography or the classics, but also as individuals with specific tastes and interests. Readers are signing up for publishers' email newsletters in the thousands; they meet with sales reps at stores and are eager to receive advance galleys, which publishers are making available to readers in the same way they supply them to reviewers and other members of the media. Traditionally, says Libby McGuire, associate publisher, trade paperbacks, Random House Publishing Group, "The bookseller controls the reader. We were never in touch with who the reader was." Now, McGuire adds, "We're in touch directly with people. We're providing a service that makes them want to be in touch with us because we're giving them things they want."

For publishers, giving groups what they want means analyzing past behavior to anticipate what will appeal to these hardcore readers. In 1999, Glaser says, Ballantine asked her for a list of the top 100 most requested book group book titles from 1996 to 1999. This list, together with updated versions, give publishers "a clue to what the public is asking for because it's generated by the community," she says. Ballantine started its Ballantine Readers' Circle in 1997. Now, the Random House Publishing Group is relaunching the line as Readers' Circle, which will now include Random House trade paperbacks. To introduce the expanded list, Random House has printed 75,000 copies of a new catalogue with 300 books, which will be updated every year. "Most of the time the trouble groups have is picking a book," McGuire says, echoing other publishers, particularly of trade paperbacks. The catalogue says, 'Here are books there will be something to talk about.' "

HarperPerennial has launched its PS (for Post Script) program, a 16-page insert that will eventually appear in nearly all Perennial paperbacks, says Perennial publisher Carrie Kania. "We're seeing it as a great tool for reading groups. They really want to know more about the author, how they wrote the book—and we know that they really use these sections when they appear online on our Web site. We're trying to give the consumer something extra—so that Perennial stands out."

And standing out is getting harder, as publishers compete to woo book clubs. Kania says the PS inserts are expensive to produce, but worth it, while McGuire acknowledges that Harper's program gives Random greater incentive to ramp up its own efforts to appeal to reading groups.

Trigiani's new novel, Rococo, is a case in point. Trigiani says that Random House asked her to write a reader's guide far earlier in the process than with her previous books. "Groups want it available from the writer and I used to do it over the course of the year it was in hardcover," Trigiani says. "Now it's a focus from the start and there's a lot more to do before your book comes out." Though the material will not appear in the hardcover copy, it will be available on the Web, for use by clubs that buy hardcovers. Putting the guides online is also a way of building anticipation for the paperback.

While trade paperback remains the dominant format for book groups, Glaser says clubs are starting to buy more hardcovers. The Jane Austen Book Club, for example, published by Putnam in spring 2004,sold more than 200,000 copies in hardcover, in large part on the strength of reading group sales (there are about 180,000 copies in print of the Plume paperback that went on sale April 26). Viking last month launched the hardcover of Kidd's The Mermaid Chair, the follow-up to the author's big book club success, The Secret Life of Bees, with the "Coast-to-Coast Reading Group Project," signing up more than 500 clubs to read the novel in April. (A sweepstakes meant signed copies for members of winning clubs, a popular perk.) Viking plans to repeat the program with other authors because it helps the hardcover but also because positioning a hardcover correctly with the clubs reaps rewards in paperback. Ballantine published Angry Housewives Eating Bonbonsby Lorna Landvickin March 2003 and arranged 50 book club chats for the author. While the hardcover sold modestly, more than 500,000 copies have been sold in trade and mass market paperback. For Landvick's April 2005 hardcover, Oh My Stars, Ballantine prepared a reader's guide and built a Web site. A current club favorite, The Shadow of the Windby Carlos Ruiz Zafon, sold 68,000 copies in its Penguin Press hardcover. This year, the Penguin paperback has over 210,000 copies in print.

Whether in hardcover or paperback, a title popular with book groups has an extended life, and sales may even increase over time. Matthew Pearl's The Dante Club, which has more than 500,000 copies in print in trade paperback, was published by Random House in hardcover in 2003 and in paperback in February 2004. In March 2005, McGuire says, it shipped more than in the previous three months. "Which is crazy for a book 14 months old," she says. "When I see consistent sales every week and there's nothing you're doing, the author's not on the road, we're not advertising—that's all come and gone, we did that—when that's happening, I say, 'reading groups.' "

Glaser points to the unusual sales pattern of another book that she says represents the power of reading groups to move titles, in particular literary fiction. Gail Tsukiyama's The Samurai's Garden, a perennial favorite of the clubs published by St. Martin's in hardcover in 1995 and in Griffin paperback in 1996, has sold 769 new copies at Schwartz (and nearly 1000 counting sales of remainders and used copies). Glaser estimates that without clubs it would have sold "maybe five copies" in her store; she said it seemed to be a book unlikely to break out beyond the author's native Pacific Northwest. Yet, because reading groups had picked up on it, she started recommending it as a starter book for clubs beginning in 1998—three years after it was published. "Word of mouth among booksellers and book groups made this book happen."

Authors also become part of that word of mouth. Book groups often ask Trigiani for recommendations; she obliges with choices tailored to a group's tastes, whether that means a holiday read, a classic or a book from another country. That makes Trigiani and other authors on the reading group circuit not only an effective promoter of their own books, but a booster of other potential reading group hits.

Trigiani's experience is becoming more typical, says Kathryn Court, president and publisher of Penguin Books and publisher of Plume. Court cites Mary McGarry Morris, whose The Lost Mother Penguin published in February, as "very good at the chatting part." Court maintains that book clubs are irrevocably changing authors' need to be in touch with readers. "The book has to be really good, but the approachability of the author is the icing on the cake. If you think of Ross King or Dava Sobel, they're so wonderful in person that even if you thought you wouldn't want to read the book, they make it accessible."

That can add up to lasting reader loyalty. Andrea Annese-Como, said her group in Clifton Park, N.Y., was surprised and delighted when Trigiani agreed to a call-in for a conversation about the author's Lucia, Lucia. "Capital Chics Book Club is still talking about our discussion. I think it was the quietest we ever were and we actually listened when Adriana spoke. Eighteen women can be loud at times. This experience gave us a true understanding of her book."

And that, as Trigiani knows, is worth getting up early for.

The Power Brokers Book club guides are one of a publisher's most favored tools for attracting the attention of reading groups, but aren't always effective. In fact, Mary Beth McKenna of the 12-woman Bookclub, in Dallas, says "Whenever I see a list of suggested book club discussion topics from a publisher, I just have to laugh and wonder, 'Have the people who write these questions ever been to a book club?' Those questions read like something you'd find in a college-level English lit class. Book club discussions tend to focus on how the plot or characters relate to our own lives or perspectives." Members of some other book clubs weigh in with their thoughts about what works and what doesn't.
LaVonne Neff
Barney's Book Babes, Glen Ellyn, IL
Membership: 40 women. ("We are Babes. So far no guys have tried to join.")
"Most of our books are either fiction or memoir. Recently we've been reading a lot of books with international themes: Reading Lolita in Tehran, The Kite Runner, Don't Let's Go to the Dogs Tonight, Mountains Beyond Mountains. We choose titles informally. We do ask that people choose books that are widely available and preferably in paperback."
Gus Alfieri
Sports Pages Roundtable, Smithtown, Long Island
Membership: 30 men
"After I formed my sports book group I found that many of the store managers were lukewarm or discouraged new book groups to be formed in their store because they saw it as extra work. I was surprised when I asked about forming a club that I knew could ring up sales, and would bring folks into their store, that they were not more encouraging.
Kathy Ellenbecker
Vienna Court Book Club, Grafton, WI
Membership:12 women
Genre:"As our club has grown so has our book horizon selection. That's really one of the best parts; we all have our own style of books we bring to share.Our club has given us each a reason on more then one occasion to read a book that we would not have chosen ourselves."
Susanne Nettesheim
Fox Point, WI
Membership:14 women—with a waiting list
"I've checked out the chain bookstores' book club recommendations, and have browsed their displays of Oprah's titles, but they're not very inspiring, and it is much less likely that their sales staff will have read a book I'm considering. I'd like to see publishers provide more discussion guides for nonfiction titles, and publish or promote more book-club-type nonfiction."—Dermot McEvoy