NEW YORK (AP) - Michelle Obama's "Becoming" is selling at a pace rarely seen for a political memoir, or any nonfiction book.

Combined hardcover, e-book and audio sales in the U.S. and Canada topped 2 million copies in the first 15 days, Crown Publishing announced Friday. By comparison, former first lady Hillary Rodham Clinton's memoir "Living History" needed a month to sell 1 million copies. Former President George W. Bush's "Decision Points" took several weeks to reach 2 million. Former President Bill Clinton's "My Life" quickly sold 1 million copies but took far longer to hit 2 million.

"Becoming," which came out Nov. 13, now has 3.4 million hardcover copies in print. The former first lady is in the midst of a promotional tour, with guests including Oprah Winfrey and Reese Witherspoon.

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