Former President Barack Obama's memoir "A Promised Land" sold more than 887,000 copies, including preorders, across all formats in the U.S. and Canada on its Tuesday release date, publisher Penguin Random House announced Wednesday.
Why it matters: The memoir has sold more copies on its first day of sale than any other book published by Penguin Random House. It looks set to be the best-selling presidential memoir in modern history.
Flashback: Michelle Obama's memoir sold more than 725,000 copies on its first day