The Silkworm, the second installment in J.K. Rowling's Cormoran Strike series (written under a pseudonym), and one of the major titles caught up in the Hachette-Amazon dispute, sold roughly 21,000 copies in its first partial week on sale, according to Nielsen BookScan, which accounts for 85% of total print sales.

The novel garnered significant media attention in the run up to its June 19 publication, not just due to its mega-bestselling author, but also because of its position at the center of the very-public HBG/Amazon standoff. (The book is published by Hachette imprint Mulholland Books.)

In the weeks ahead of its publication, the book was unavailable for preorder on Amazon, whose sales are included in Nielsen's tally. On June 19, The Silkworm was available for purchase, with shipping delays reaching up to two months. As of June 25, the shipping delays are estimated at one to two days.

The early reports from all retailers have been "terrific," according to Nicole Dewey, v-p and executive director of publicity at Little, Brown, adding that the book debuted at #1 on this week's National Indie bestseller list.

When combining hardcover and e-book sales, Silkworm was also the #1 fiction title at Barnes & Noble last week. In a conference call discussing results for the fiscal year, B&N executive Mitch Klipper said the company has seen an uptick in sales of all Hachette titles since the publisher’s dispute with Amazon became public, though he declined to be any more specific than that.

The book is also performing well digitally elsewhere. It has hit as high at #6 on Amazon's Top Paid Kindle titles. It ranked second on Apple's iBooks bestseller list for the week ended June 23, one-upped only by The Fault in Our Stars, which has been nearly unstoppable on Apple's chart in recent weeks.

Once word broke last summer that the first book in the series, The Cuckoo's Calling, was penned by the woman behind Harry Potter, sales skyrocketed. The Sunday Times outed Rowling on July 14—the novel, which was selling under 100 copies per week after its April publication, sold 3,630 copies the week ended July 21, and over 65,000 copies the following week, according to BookScan. The book has sold over 320,000 copies to date.