This is a research-in-progress paper concerning the activity of book publishers and authors on Twitter. The work is based on a sample of book titles (N=2,672) published between 2014 and 2018 (up to and including October 1, 2018), and extracted from the Web of Science Book Citation Index. Our motivation is to learn more about book publishers as promotional agents. While we know that scholars often use Twitter to promote their research articles, and may do so with monographs/series titles, little is known about publishers. Scholars may Tweet about their monographs to gain visibility and increase citation counts. Publishers of the same titles might also do the same, but they are co-stakeholders in this communication process with other interests. With our pilot dataset, we have found that only 42% of the titles retrieved from the BKCI possessed DOI's and had received Twitter mentions. We have also found that if the author of a book initiates a Twitter mention, other general Twitter users are likely to make follow-up/re-tweets about the title. Book publishers, on the other hand, do often initiate Tweets, but they are less often as likely to make a re-tweet of a book title if the author or another user initiates.