When Canadian engineer Peter Hudson started BitLit Media two years ago, a big part of the idea was to start an app (now known as Shelfie) that would enable readers to get a heavily discounted or free copy of an e-book by taking a picture of their bookshelf. Hudson built on that premise this fall with the addition of Shelfie Recommendations, a part of the app that Hudson hopes will be an alternative to PWBTAB (people who bought this also bought) recommendations, which have long been used for online book discovery.

For Hudson, making recommendations is not just a matter of gathering lots of data but also of making the right spatial associations based on the books people shelve next to each other. He has viewed hundreds of thousands of photos of bookshelves that users have uploaded on Shelfie. “People don’t shelve books at home by BISAC codes,” he said. The app works by having readers take “selfies” of their bookshelves to get free, or low-cost, e-editions of the books they own. The app uses the photos to identify the covers of new and backlist titles and then notifies the user about which of their physical books qualify for free or discounted e-editions.

Hudson is excited about Shelfie Recommendations, which is now available for both Android and iOS. “We know the spatial associations of how millions of books are organized,” Hudson said. “People who own this also have this on their shelf. It’s the same reason Spotify is so good. Spotify used the 10s of millions of playlists that its users had handcrafted to drive music suggestions. People who have this song on a playlist also put these songs on their playlists. Readers have found books for centuries through serendipitous discovery and personal recommendation. The solution is simply to reimagine what already works for a digital experience.”

While Hudson continues to refine book discovery, he has not lost sight of the app’s original mission: to help readers bundle free and low-cost e-editions of the physical books they own. At present, about 1,200 traditional publishers supplying more than 200,000 titles have signed on to be part of Shelfie, and Hudson continues to talk to other publishers, including self-publishers. An announcement of new partnerships with Big Five publishers is expected soon.

Although Shelfie has been operating since 2013, the same year that Amazon launched Kindle Matchbook (which encourages customers to buy deeply discounted Kindle e-books of physical books), Hudson dates Shelfie’s real launch to this past spring. By then, parent company BitLit Media had signed two of the Big Five publishers—HarperCollins and Macmillan—along with Baker Publishing, O’Reilly Media, John Wiley, Andrews McMeel, Elsevier, and many smaller presses, including launch partner Morgan James. Another early partner, Independent Publishers Group, recently rolled its full distribution client line into Shelfie. In September, Shelfie created an alliance with Ingram’s Lightning Source that added more titles to the program.

Currently, the Shelfie app is able to identify over 95% of the titles on a book shelf. Of those, Shelfie likely has a partnership with the publishers of 10% to 20% of the books—more for its most popular categories: science fiction, fantasy, business, technology, and Christian. According to Hudson, roughly 30% of publishers offer the bundled e-book for free. Others cost 81% less than the Kindle e-book, with discounts for technical books closer to 95%. Shelfie is free to users and publishers; the company makes its money by taking a commission on each e-book sold.

BitLit is based in Vancouver and also has a San Francisco office. As Hudson, who splits his time between the U.S. and Canada, sees it, bundling has strong sales potential for independent booksellers in both countries. Two summers ago Shelfie ran a pilot with seven indies in the U.S. and 13 in Canada. “We wanted to find out what’s the effect of bundling an e-book for free with a [backlist] print book,” Hudson said. Participating booksellers pulled backlist titles, stickered them to indicate that they were eligible for the free bundled e-book deal, and displayed them in the front of their stores for two months. According to Hudson, featured books got a 180% sales lift.

“We’d love to do something more with indie booksellers,” Hudson said. “They know how to push paper books. Bundling, in the way we do it, allows them to sell digital by selling print.” Hudson acknowledges that he hasn’t yet worked out what the next step with booksellers may be, but he said he is in touch with some about trying Shelfie again.

Whether or not Shelfie can make, in Hudson’s words, “online book discovery not suck,” it continues to provide an opportunity for book bundling and for generating conversations about books. TechCrunch recently compared the app’s ability to recognize books, both old and new, to “Shazam for your bookshelf.” It’s the same ability that got author Joe Hill so excited when he first tried it that he asked his publisher, HarperCollins, to make his e-books available for free as part of an early Shelfie pilot. As Hill Tweeted to his followers, “If you haven’t... given Shelfie a try, you’re missing out on some righteous tech.”