In publishing and politics, timing is everything. And when the two come together, a star may be born. That's been the case with Sen. Barack Obama, D-Ill., and his second book, "The Audacity of Hope." Booksellers and political observers have been buzzing for months about the rock-star atmosphere at the Hawai'i-born Obama's appearances to promote the book.

But what, if any, influence has book sales had on Obama's plans to run for president? (So far he has formed a presidential exploratory committee.)

"Reaction to the book and the response he received on the tour contributed to his thinking about the presidential race, but it wasn't timed for that purpose," says David Axelrod, a political consultant to Obama.

Obama signed on to write the book long before the idea of running for president ever surfaced, Axelrod says. "There is no question, however, that the book signings and accompanying forums gave him a great opportunity to interact with thousands of people throughout the country."

The book's success is attributed to its intimate, personal style. It's a lesson other politicians can learn from, historian Douglas Brinkley says: "You don't want a book to sound like something ginned up by a Senate staff or a governor's ghost writer."