Departing from Marshal McLuhan’s analysis of the impact of print books on the mental and social environment of readers, Arjen Mulder reflects on the possible mental and social effects of the e-book as a new medium. The e-book, as carrier of an immaterial text, allows the reader to change its lay-out, font and other design elements. Additionally, e-books contain not just one single novel but an entire library and even contain an online bookstore. Another prominent effect of e-books is that they cause discrepancies between the actual reading experience and the user experience of the medium. Mulder also analyses some of the disadvantages of this new medium due to its technical properties. These concern for instance the integrity of the text, the unreliability of the technology, or the fact that providers can without any permission reinitialise your e-reader and therewith delete your entire e-book library. Mulder concludes with a discussion of the different reading modes available to readers to read print and electronic texts.