The success and mainstreaming of e-books is transforming not only the traditional/Gutenbergian idea of the book but also the previous idea of an e-book as mainly an enriched print book. In the new e-book concept, the nature of a book as an artifact is diminishing and disposition as a networked interface to the knowledge is rising. One of the most important emerging concepts is the social reading, which means reading acts while connected to the other people. Social reading is a new and not very well defined area of reading practices. In addition to the traditional reading together and discussing books person to person, social reading includes a large number of networked functions like sharing and receiving shared information. Research of this new phenomena is almost non existent, yet it is expected to be the next big thing in reading and in e-books. This study provides an overview of the history of social reading of printed books and then defines parallel features in the new digital reading activities. Research material consists of popular e-book software and services. The proposed categorization of social reading is based on content analysis of properties that were found in those services. This report claims that social reading functionalities are manifestations of the social needs that have existed during and even before the paper book; digital time enables re-emerging of some of those features, but in a different manner.