Book authors have been searching eagerly for ways to harness social media to promote their works. So it would seem that Gregory Levey had stumbled upon the magic key after the Facebook fan page of his book went from having just 700 fans to 692,000 in a matter of months — more than New York City (570,000 fans) or the George Clooney fan page (613,000).

“I couldn’t believe what I was seeing,” he wrote in a recent essay on a Web site for authors about the explosion in his book’s popularity. “Who were these people?”

But Mr. Levey, 32, quickly realized that his book, now two years old, had not catapulted to the best-seller list or landed on Oprah’s Book Club. Rather, somehow, people had fastened onto the book’s title — “Shut Up, I’m Talking” — and taken it in an unintended direction. People weren’t telling their friends that they “Like” his page because they were avid readers; instead, they were fans of the catchphrase.

Then Mr. Levey started examining his new online entourage: They were the same people who say they “Like” pages such as “Shocking: Tattoo misspellings you have to live with!” Worse, many of his fans unabashedly proclaim on their own Facebook pages that they don’t read books.

Mr. Levey’s book — whose full title is “Shut Up, I’m Talking: And Other Diplomacy Lessons I Learned in the Israeli Government” — chronicles the story of how he landed a job as a speechwriter on the staff of then Prime Minister Ariel Sharon while he was a 20-something law school graduate.

Certainly, his publisher says any exposure, even accidental, can be good.

“Facebook is a medium that fascinates thousands and is a curiosity even to those folks who don’t subscribe to it,” said Carisa Hays, vice president and director of publicity at Simon & Schuster/Free Press.

Ms. Hays and Mr. Levey acknowledge that they haven’t seen a spike in sales as a result of his Facebook groupies. He has a new book, scheduled for release on Sept. 7, “How to Make Peace in the Middle East in Six Months or Less Without Leaving Your Apartment,” also from Free Press. He has started a new Facebook page, Peace in the Middle East, which he hopes will draw a more thoughtful — or at least book-buying — crowd.

“There’s clearly power there,” he said.