"Cathy's Book: If Found Call (650) 266-8233" is scheduled to be in bookstores' young-adult sections next month. Cathy is a budding artist who turns to sleuthing to find out why her boyfriend dumped her. The innovative book uses working phone numbers and websites and a packet of "evidence" to send readers on an interactive scavenger hunt.

Yet it is the book's behind-the-scenes deal - brokered before publication between Running Press, a subsidiary of Perseus Books Group, and Procter & Gamble, maker of CoverGirl cosmetics - that set off alarms among some booksellers, authors and child-advocacy groups.

While recent teen books such as the "Gossip Girl" and "A-List" series liberally mention brand names, "Cathy's Book" is the first to use prearranged product placement - in this case, mentions of specific lipstick and eye makeup shades worn by the title character - in exchange for promotional exposure by Procter & Gamble.

For some, such an advertising arrangement is unconscionable, breaching the sacred ground of children's literature.

"I think this is the top of the slippery slope we've been climbing for some time now," says Kristen McLean, executive director of the Association of Booksellers for Children.

While careful not to criticize Running Press for its decision, she worries about the precedent being set. She calls it the next step in "branding," or creating product loyalty. Studies show children as young as 2 can recognize brand logos and make requests for the goods.

Product placement, such as leaving a Pepsi can on the table or having a character eat Frosted Flakes, is a highly effective advertising device used in movies and television to promote brand names. For a fee, makers get their products inserted into scenes. Research shows that viewers tend to favor what they have seen.

In the case of "Cathy's Book," no money changed hands, the publisher insists. Instead a cross-promotional deal was struck after Procter & Gamble was shown a manuscript by the authors. Because of the shared target audience, a handful of references to actual makeup products were sprinkled into the text and illustrations, explains Rick Joyce, marketing director of Perseus Books. He says it adds realism.

Once the book is released nationally Oct. 11, it will be promoted by Procter & Gamble on Beinggirl.com, a P&G-sponsored website aimed at adolescent girls. It discusses puberty, boys and makeup.

Last week, the Campaign for Commercial Free Childhood, a Boston nonprofit group, launched a national effort to force the publisher to remove mentions of CoverGirl. In two days, more than 500 e-mails were sent in protest to Running Press, the group reports.

"Books, up to now, have been a refuge from commercialism," says Susan Linn, a psychologist and co-founder of the group. She worries, too, about the implications for parents.

"It has always been that with the electronic media, parents are supposed to limit access (to control commercialism). Are they now supposed to limit access to books?"

Commercial Alert, an Oregon watchdog group, urged book reviewers to treat "Cathy's Book" not as a novel but as a business story.

Others, though, remain puzzled, if not irritated, by the fuss.

"Let the book stand on its own," says Shelly Wilhelm of The Bookies, a children's bookstore in Denver. She has been following the buzz on the Internet and will stock the book. "To not do so becomes a censorship issue."

She and others say licensing arrangements and commercial tie-ins to children's books have existed for years, including books based on movies, cartoons, toys and food. In 1998 a toddler book was released that featured Cheerios as a counting tool.

And in the world of grown-up books, best-selling author Fay Weldon was paid in 2001 by Italian jewelry maker Bulgari to weave a tale around its brand. The book was called "The Bulgari Connection."

"I see it as inevitable," says McLean of the Association of Booksellers for Children. "Big marketing firms are realizing the effectiveness of traditional forms of advertising are breaking down. They are going to try new things to reach people."

Joyce, of Perseus Books, agrees. He embraces the changes he sees coming in books for children, especially teens.

"You're going to see a lot more books that are not content to just be books. The younger audience doesn't want to passively sit in a chair and read anymore," he says.

He says his publishing house already has signed a similar deal with Sean Stewart and Jordan Weisman, the authors of "Cathy's Book." Both men have computer gaming and marketing backgrounds.

Joyce says the product-placement arrangement with Procter & Gamble is only a minor component to the book. He says the criticism has overshadowed the good of the book, which is helping to reach teen readers. "It lives where teenagers live - with a mouse in one hand and a cellphone in the other."

Margaret C. Campbell, an associate professor of marketing at the Leeds School of Business at the University of Colorado, is worried less about product placement in books and more about full disclosure.

Consumers not only favor products embedded in movie and TV scenes, she says, they often dislike fictional products because they say it makes a show seem less realistic.

But they don't like to be tricked either, says Campbell. Research has shown the effects of product-placement advertising are somewhat mitigated if viewers know a deal has been struck to put the products there.

Joyce says the deal with Procter & Gamble has always been fully disclosed. A small nod to CoverGirl appears on the copyright page of "Cathy's Book," written in the vernacular of the title character to her pal:

"Emma thought the good folks at CoverGirl and BeingGirl.com would kick-start my career and help get the message out. ... Thanks, guys."