It is reported that Rowling sent the manuscript to the publishers anonymously and that it was declined by at least one publishing house, including Orion Books. It was eventually accepted by Sphere Books, which is an imprint of Little, Brown & Company, with whom Rowling had collaborated on her previous novel, The Casual Vacancy.
Before Rowling's identity as the book's author was revealed, 1,500 copies of the book had been sold since its release in April 2013. The book surged from 4,709th to the 1st best-selling novel on Amazon after it was revealed on 14 July 2013 that the book was written by Rowling under the name "Robert Galbraith".
.. However, it was later reported that Rowling's authorship was leaked to a Times reporter via Twitter by the friend of the wife of a lawyer at Russells Solicitors, who had worked for Rowling. The firm has since apologised.
After being revealed as the author, Rowling said that she would have liked to remain anonymous for a while longer stating that, "Being Robert Galbraith has been such a liberating experience… It has been wonderful to publish without hype and expectation and pure pleasure to get feedback under a different name."
I sympathize with J.K. here as authors can become the victim of their own success. While I never believe that J.K.Rowling has any remarkable talent, I did applaude her from trying to start from scratch again instead of using her fame. However this exercise in futility only proves that, ultimately, it is the author's name that sells the book. The sale of her crime novel was medicore at best until her pseudonym was revealed and now the book is getting the attention that it most likely didn't deserve.