I was actually shocked by this number. Adult hardcover sold 55 mil in the same month, meaning that e-books, given their "new to market" status is just months from overtaking adult hardcover sales. Having some hard numbers really puts this in perspective for me. Time to choose an e-reader, folks...
Hardcover books - not.
I mean, seriously, how many parents buy a heavy hardcover book for kids. A lot of that "trade" was the Harry Potter series and .. it's over.