J.K. Rowling's pseudonym allowed her to write a crime novel called The Cuckoo's Calling undetected.

J.K. Rowling used a pen name, Robert Galbraith, to publish the crime novel The Cuckoo's Calling.

Rowling found using a pseudonym "freeing" because she was able to get feedback without hype.

Rowling reportedly said, "I had hoped to keep this secret a little longer because being Robert Galbraith has been such a liberating experience. It has been wonderful to publish without hype or expectation and pure pleasure to get feedback under a different name."

The book had only sold 1,500 when the news broke, but the Amazon sales have skyrocketed by 150,000%. A second Galbraith book is to be published next year.

The text was published by Sphere in April in the UK. Sphere, a Little, Brown imprint, also published The Casual Vacancy, Rowling's first post-Harry Potter fiction novel.

J.K. Rowling's pen-name-penned The Cuckoo's Calling is about Cormoran Strike, a one-legged detective investigating the death of a supermodel named Lula Landry. The book's Amazon blurb reads, "You may think you know about the wealthy and famous, but you've never seen them under an investigation like this."

Harry Potter fan site The Leaky Cauldron says the book has so far sold just 1,500 copies, and that a second Galbraith book is to be published next year. Update: Since the news broke, New Statesman reports that the book's Amazon sales have gone up more than

The book got a rave review in Publishers Weekly when originally released. They said that, "in a rare feat... Galbraith combines a complex and compelling sleuth and an equally well-formed and unlikely assistant with a baffling crime in his stellar debut."

It's not the first time Rowling used a pseudonym of sorts.  When she first sold the rights to Harry Potter, Rowling had to use the gender neutral initials J.K. because books written by men sold better. Her fictitional biography for the current book said,

Born in 1968, Robert Galbraith is married with two sons. After several years with the Royal Military Police, he was attached to the SIB (Special Investigation Branch), the plain-clothes branch of the RMP. He left the military in 2003 and has been working since then in the civilian security industry. The idea for protagonist Cormoran Strike grew directly out of his own experiences and those of his military friends who have returned to the civilian world. 'Robert Galbraith' is a pseudonym.