The former first lady's pillow-talk confessions and intimate testimony of her years at the White House, backed up by an aggressive global publicity tour, was hailed a publishing sensation last month.

Just nine days after Senator Clinton's book release Oprah revived her book club, selecting John Steinbeck's novel East of Eden. That very day Steinbeck's 51-year-old classic leaped to No 2 on internet bookseller Amazon.com's bestseller list, leapfrogging Mrs Clinton and chasing the record-breaking latest Harry Potter. Within a couple of weeks it had sold 750,000 copies and shot to the top of the New York Times fiction paperback bestseller list.

Penguin now has in print 1.2m copies of the book, a symbolic recreation of the biblical story of Cain and Abel woven into a history of California's Salinas valley. It is a great victory for Winfrey, who suspended her last book club after a spat with the author Jonathan Franzen, who asked to be taken off her list.

"I'm back in the business of recommending books...but with a difference," she told the Association of American publishers in Washington in February, where she was being honoured with a lifetime achievement award.

Within a week of the club's relaunch, 115,000 members signed up. Winfrey said it was Steinbeck's work that had prompted her to revive the club: "I was literally halfway through East of Eden and thought, 'Gee, I wish I had a book club again.'"