Amazon, which made its fortune selling other publishers’ books, is now pushing hard into the business of signing up and publishing its own authors, in both digital and print. Since 2009, it has launched six new imprints (see chart) and hired publishing industry veteran Larry Kirshbaum, the former CEO of Time Warner (NYSE: TWX) Book Group (now Hachette) to head up a seventh. All of this has led to a spate of breathless headlines, especially following a recent New York Times piece about Amazon’s publishing program. “Wake up and smell the disruption,” Mathew Ingram wrote at GigaOm. “Amazon is coming for the book publishing industry. And not just the e-book world, either,” wrote Noah Davis in a Business Insider post under the headline “Amazon Invades The Publishing World, And Publishers Are ‘Terrified’.” And Glyn Moody at Techdirt called Amazon’s efforts “a fully-integrated global publishing strategy.”

Yet beyond these bullish prognostications, there’s been little effort to gauge the success of Amazon’s nascent publishing efforts. The company has published about 150 books since 2009, ranging from literature in translation to romance and thrillers. Many of the authors had previously self-published their books; others left traditional publishers to work with Amazon.

Piecing Together Sales Data

How have these books sold? It’s not an easy question to answer. While Nielsen BookScan tracks print book sales, it hasn’t yet begun tracking e-book sales, at least not for public consumption (it began providing data for the Wall Street Journal‘s new e-book bestseller lists just last week). The books’ authors know how many copies they have sold, but they sign non-disclosure agreements when they sign up as Amazon Publishing clients. And Amazon is notorious for providing very little in the way of sales figures for its books—or its Kindles, or anything else it sells.

So I decided to try to piece some of this information together on my own, through the book product pages on Amazon.com. Using Books Advanced Search, I found all of the titles available from each Amazon imprint. I entered those titles into a spreadsheet including title, author, imprint, publication date, print book price, e-book price, number of reader comments and average star rating.

I found that Amazon Publishing has released 149 titles across its first six imprints since 2009, with an additional 114 slated to be released between November 2011 and October 2013. Meanwhile, Amazon told me it will release “more than 100 titles” this fall, which suggests that some planned titles aren’t yet on the website. The 263 titles I tallied, though probably not the complete list, still provide a fairly comprehensive look at what Amazon has published so far and where it is headed. Here are some of my findings:

»  261 of the 263 titles are available as print books as well as digital books.

»  Print almost always means trade paperback. I found just 13 titles available in hardcover.

»  The average sale price of an Amazon Publishing paperback is $9.92. (The average price of a trade paperback in 2010 was $10.14, according to publishing research firm R. R. Bowker.)

»  The average price of an Amazon Publishing e-book is $6.91. (The average price of an e-book in 2010 was $5.75, according to Bowker.)

»  The books are heavily reviewed by customers (more on that later). Amazon Publishing titles have, on average, 47 reviews, with an average star rating of 4.09.

»  Publishers have long built up their backlists (and their profits) by buying the rights to out-of-print titles—and Amazon is doing the same. At least 49 Amazon Publishing titles were previously published by other houses between 1953 and 2009: Avon, Ballantine, Bantam, Delacorte, Dutton, Harcourt, Henry Holt, Houghton Mifflin, Little Brown, NAL, Random House, St. Martin’s and William Morrow. As far as I can tell, the only publicized deal of this nature was Amazon’s agreement with Toby Press: In 2010, Amazon acquired the print and digital rights to 121 of its literary fiction titles. (I found 20 of those titles currently for sale.)