Little did President Obama know that by accepting an early copy of “Freedom,” the new Jonathan Franzen novel, he would set off a small panic in the publishing world.

On Friday afternoon, as Mr. Obama settled into his vacation on Martha’s Vineyard, he and his daughters stopped off at Bunch of Grapes, the renowned bookstore in Vineyard Haven. As he bought copies of “To Kill a Mockingbird,” by Harper Lee and “The Red Pony,” by John Steinbeck, booksellers handed him an advance readers copy — or A.R.C., in publishing lingo — of “Freedom,” the hugely anticipated book whose release is embargoed until next Tuesday. Booksellers are provided with advance copies of books weeks or months ahead of publication.

Media organizations quickly reported that Mr. Obama had bought a copy, sending off alarm bells (and their modern counterparts, Google news alerts) at Farrar, Straus & Giroux, Mr. Franzen’s publisher, whose spokesman, Jeff Seroy, quickly contacted reporters to correct the record. CBSnews.com updated its story, implying that the White House had provided incorrect information.

It might have been too late. Other bookstores, believing that Bunch of Grapes had broken the embargo, threatened to sell the book early. Rumors swirled that Farrar, Straus would move up the on-sale date. Eager readers who saw that Mr. Obama had the book in hand tried to get their own copies, only to be told that it wasn’t on sale yet. “People are confused,” said Jake Cumsky-Whitlock, a manager at Kramerbooks in Washington, who personally fielded a handful of requests for the book on Sunday. “One gentleman was somewhat indignant. He was sure that we were wrong.”

Sam MacLaughlin, a bookseller at McNally Jackson in Manhattan’s SoHo district, said that many customers had been asking for copies. “I’ve been trying to foist ‘The Corrections’ on them in the meantime,” he said, referring to Mr. Franzen’s best-selling novel from 2001. Mr. Seroy of Farrar, Straus said that for now the publisher was sticking to the plan to publish Aug. 31 despite the fact that a torrent of reviews and articles have been written about the book, leaving the public with the impression that it is already for sale.

And he did not complain that Mr. Obama has been linked publicly to “Freedom.” “You can’t pay for that kind of publicity,” he said. “You can’t even dream of it.”