J.K. Rowling’s secret book shoots up bestseller lists after she’s outed on Twitter

Want to read a new mystery by bestselling Harry Potter author J. K. Rowling? You’re in luck, and you don’t even have to wait: She published a mystery, The Cuckoo’s Calling, under the pseudonym “Robert Galbraith” in April, and was outed by the Sunday Times of London (paywall) over the weekend.

Now that the secret’s out, Cuckoo is shooting up bestseller lists. The book, which was published by Hachette’s Little, Brown imprints in the U.S. and U.K., is now #1 on Amazon’s Kindle list and #2 on the print book list; #1 on Barnes & Noble’s print list and Nook (s BKS); and #1 in Apple’s iBookstore (s AAPL). They’re all selling it for $9.99, down from a digital list price of$12.99.

Cuckoo, the story of a war veteran turned private investigator, sold only 1,500 copies in the U.K. and 1,800 in the U.S. before Rowling was outed. As for how that happened, thank Twitter. The New York Times explains:

“It started on Thursday, said Richard Brooks, the paper’s arts editor, after one of his colleagues happened to post a tweet mentioning that she had loved ‘The Cuckoo’s Calling,’ and that it did not seem as if the book had been written by a novice.

‘After midnight she got a tweet back from an anonymous person saying it’s not a first-time novel — it was written by J. K. Rowling,’ Mr. Brooks said in an interview. ‘So my colleague tweeted back and said, “How do you know for sure?”

The person replied, ‘I just know,’ and then proceeded to delete all his (or her) tweets and to close down the Twitter account, Mr. Brooks said. ‘All traces of this person had been taken off, and we couldn’t find his name again.'”

Brooks then poked around online and found that Cuckoo and Rowling’s previous novel for adults, The Casual Vacancy, had the same agent, editor and publisher. And he sent copies of those books, plus Harry Potter and the Deathly Hallows, to “a pair of computer linguistic experts, who found significant similarities among them.” A Rowling spokesperson then admitted it.

“I hoped to keep this secret a little longer, because being Robert Galbraith has been such a liberating experience,” Rowling said in a statement. “It has been wonderful to publish without hype or expectation and pure pleasure to get feedback from publishers and readers under a different name…And to those who have asked for a sequel, Robert fully intends to keep writing the series, although he will probably continue to turn down personal appearances.”