It's no secret that Waterstones has struggled to sell e-books, but then it could never make it particularly convenient for customers to buy them. After making a purchase, they've had to download a file and manually transfer it to an e-reader, or use a third-party app for smartphones and tablets. In other words, not exactly the simple and seamless experience Amazon and Kobo's ecosystems offer.

Today marks yet another digital departure for Waterstones, which first started stocking Sony e-readers way back in 2008. The bookseller was even working on its own e-reader at one point, before giving up on that idea and welcoming Amazon's Kindles into its stores instead. But last year Waterstones ended the partnership, citing "pitiful" sales.

The deal with Waterstones is another chapter in Kobo's story, too. The company might be known for its popular e-book platform and competitive e-readers, but it's also made quite the habit out of assimilating the customers of defunct services. Like some kind of e-book store Highlander, it's already absorbed Sony's Reader division and Blinkbox Books, which Waterstones was actually in talks to buy at one point.

With Kobo on hand to support customers, Waterstones can get back to focusing on selling physical books. And the company couldn't have heard better news a few weeks ago, when The Publishers Association announced that sales of printed books rose in the UK last year, while e-book sales declined for the first time since its records began.