I have an old blog post on this topic from the attentional value side of things, about reading on paper vs. reading "online." A Kindle can hold more books than can fit in my house, but lack of a physical presence beyond that black slab of plastic is a weak link in remembering what's in my collection, what I'm currently reading, or even to remember to get back to it.
A book on my nightstand or desk is much more likely to get the proper continuity of attention, and triggers a greater engagement with the senses. Especially an old used book that may have seen it's third round through second-hand bookstores.
Despite what may be more economically and distributively efficient, it's just as with writing vs. typing, we are wired to have more of the mind engaged with the former. We value (not in the monetary sense but in how we relate to it) mediums with more presence.