Take a walk through a bookstore, and I bet you will find a surprising amount of books displayed on the shelves that used to be something else before they were also books. Perhaps they are also Instagram profiles, popular blogs, YouTube channels, Tumblr accounts, or Tweets. There is a trend in book publishing where publishers are sourcing new book concepts from pre-existing media content, particularly digital content. This trend aligns with the rise in print book non-fiction sales over the past year. This rise in sales especially included memoir, cookbooks, and photography books—all books commonly sourced from digital material.

When so much original content is accessible for little to no cost online in digital form, why is that this content is being turned into and sold as physical books, and what does this say about the value of a book? Why would someone buy the book when they can get the content for free? After much research, I have found a few main reasons why someone might be willing to pay for one of these books.

For starters, books are used as collectibles. The psychology behind the desire to own and keep a physical object is part of the reason why we collect physical books. In a study about preferring physical books over ebooks conducted by the journal Electronic Markets, focus group participants reported that they use their physical book collections to express their identity to guests who may see their bookshelves.

Another contributing factor for the phenomenon of making books out of digital content could be the movement of reviving old media as a part of a postdigital revolution—a trend holding on to the technological past. The postdigital phenomenon suggests that millennials, in particular, are keen to use outdated technology as novelty items as a way of rejecting the digital revolution. Some examples of this include the resurgence of Polaroid cameras and the recent rise in vinyl record sales.

Lastly, books can be tokens of personality. Perhaps people buy them as tokens of fan dedication to the influencers who write them. These books may be used as real-life souvenirs of virtual experiences. They are a physical reminder to ourselves and others of how that experience helps formulate our identity.

There is no shortage of examples of influencers’ digital content being transferred to the physical page. Instagram, blogs, YouTube, Twitter, and webcomics have all inspired the creation of print books. Some examples include, but certainly aren’t limited to, The Dogist (Instagram), This Book Loves You (YouTube), and The Donald J. Trump Presidential Twitter Library (Twitter). Perhaps this strange concept can be mutually beneficial for both the consumer and the publisher. How can acquiring these types of books be useful for marketing teams?

Publishing influencers as authors and popular content as books has useful marketing advantages. A book that is easily marketable is less of a risk for a publisher to acquire because books easily marketed are books easily sold. In the case of most of the books mentioned previously, the author worked as a spokesperson for their book. These authors, or influencers, also were taken on by publishers because they had a built-in following. There is a pre-existing audience for their book, and publishers will have to make little to no effort to reach that audience. Along with these pre-existing audiences come fans and established online communities surrounding the influencer and their content. As many marketing professionals know, fans serve as excellent grassroots intermediaries for spreading word of mouth publicity for a book.

Another important marketing advantage for these books is their established brands. They come with a pre-formed brand aesthetic because digital content is typically visual content. Solid branding, especially in social media, is proven to be effective in marketing books. Books with well-branded authors and a strong social media presence tend to be more successful. It is also important to know that their already-existing metadata makes them already identifiable and searchable online.

Bookstores are also embracing digital media-based content, which makes it easy for the customer to locate and easy for the publisher to market. Barnes & Nobel once posted an article about “Bestselling Books By Our Favorite YouTube Stars.” Bookstores also have been known to make in-store displays playing off the theme of social media content becoming books.

By factoring in recent sales trends and rising competitiveness between new books being published, I believe it is safe to say that sourcing new book concepts from existing media will continue to play a major role in the future of book publishing.