I love this tool, brought to my attention by reader Ian Lamont. You can view the ISBN visualization here.
He notes, “One very practical use of this system is the ability to quickly see all of the books published by a single publisher in a specific reserved block as well as all of the unassigned ISBNs in that block. It would be a useful tool for researching a publisher’s historical output as part of due diligence. Note that the tool doesn’t reflect duplicate ISBNs (something I was unaware of until reading this).”

Jane Friedman has spent her entire career working in the publishing industry, with a focus on business reporting and author education. Established in 2015, her newsletter The Bottom Line provides nuanced market intelligence to thousands of authors and industry professionals; in 2023, she was named Publishing Commentator of the Year by Digital Book World.
Jane’s expertise regularly features in major media outlets such as The New York Times, The Atlantic, NPR, The Today Show, Wired, The Guardian, Fox News, and BBC. Her book, The Business of Being a Writer, Second Edition (The University of Chicago Press), is used as a classroom text by many writing and publishing degree programs. She reaches thousands through speaking engagements and workshops at diverse venues worldwide, including NYU’s Advanced Publishing Institute, Frankfurt Book Fair, and numerous MFA programs.


