J.K. Rowling’s magicless novel for adults sold 375,000 copies in its first week out, according to Little, Brown. (Nielsen BookScan has the number at 157,000, though it only tracks 75 percent of the print retail market.) For comparison, Harry Potter and the Deathly Hallows sold 8.3 million copies in the United States in its first day, and Fifty Shades of Grey is at 25 million and counting in 2012. But also: 375,000 is a lot of novels, and J.K. Rowling is a billionaire.