JK Rowling's new detective novel, The Silkworm, finally available on Amazon

Rowling's detective novel - The Silkworm - was in the top 100 by late Thursday for both print and e-book sales. She wrote it under the pen name Robert Galbraith.

JK Rowling's latest novel has quickly climbed up the best-seller lists now that it's finally available for purchase on Amazon.com.

Rowling's detective novel - The Silkworm - was in the top 100 by late Thursday for both print and e-book sales. She wrote it under the pen name Robert Galbraith.

Thursday was the book's official publication date, but it couldn't be ordered before then through Amazon because the online retailer and Rowling's US publisher, Hachette Book Group, are arguing over e-book terms. Amazon delayed shipments for some books by Hachette authors or made the releases entirely unavailable.

Buying The Silkworm in hardcover still isn't without some frustration: Customers were told delivery would likely take 2-4 weeks.

Barnes & Noble's website ranks The Silkworm No. 1 for print and No. 5 for e-books.