Here are some social media platforms that can help you promote your book for free. Although they allow promotion, most of these platforms are not strictly promotional. Their main purpose is to host discussion groups, book clubs, and writing critique groups.
In addition to the ever-present necessity of promoting your work, I would encourage you to take advantage of these non-promotional functions for two reasons: 1) As a writer, it's essential to participate in discussions about your craft and genre, and 2) You may make some valuable contacts with other authors in the course of those discussions. (I did.)
Facebook is a huge social media platform, which means it can produce dramatic results. First, set up a page for your book. (This is a must.) Then join writers' groups. The largest and most active writers' groups are listed here: 43 Facebook Groups for Authors. There are also several active Facebook groups geared specifically to science fiction and fantasy writers. These are:
Fantasy & Science Fiction Writers in America. (Closed group) This is for writers who focus their work mainly on science fiction and fantasy. The site is for writers to post small pieces of their work to get others' opinions on them, to offer or request advice about the art, craft, and business of writing, and to exchange interests concerning science fiction and fantasy writing with like-minded individuals.
Cyberpunk Science Fiction & Culture (Closed group) Group dedicated to all things related to cyberpunk: culture, literature, music, film, technology, games, fashion, lifestyle, etc.
Science Fiction and Fantasy Authors. This group is open for anyone who loves the genres of science fiction and fantasy. They welcome readers, writers, viewers and all lovers of the genres.
Science Fiction. (Closed group) For all those interested in science fiction and fantasy adventure reading.
Space Opera. Space opera is a sub-genre of science fiction dealing with stories of epic adventure and conflict on a grand scale. If you are a fan of authors like Poul Anderson, Peter F. Hamilton, Alastair Reynolds, E.E. Smith, David Drake, Neal Asher, John C. Wright, Iain M. Banks, Walter Jon Williams, Dan Simmons, Jack Vance, David Weber, Vernor Vinge, Stephen Baxter, Larry Niven, or Louis McMaster Bujold, this group is for you. Authors can promote their books through special promotion threads.
Science Fiction and Fantasy Books Fans. This is a virtual book club of fans of science fiction and fantasy.
SciFi,Horror,Endoftheworld,Truestory.,other,Books,Screen,Music,Writers. This group is for authors, novelists, screenwriters, and bloggers to share their pages and/or published work.
#PNR (Paranormal Romance)
#IFNRTG (Indie Fantasy Re-tweet Group)
#IARTG (Indie Author Re-tweet Group)
Reddit is underutilized for promotional purposes, probably because the site actively discourages self-promotion and ads. Nevertheless, several authors have been "discovered" on Reddit, and have developed sizable fan bases, usually through r/books and its subreddits. (The trick to Reddit is knowing which sub-reddit is appropriate for your topic.)
r/books. This is a very active community dedicated to the world of books. There are no direct promotions allowed on this page, but they do have a “new releases” section where you can promote your book. You are allowed to promote your own writing in "new releases" as long as you follow these two rules:
- The books being discussed must have been published within the last three months OR are being published this month.
- No direct sales links.
r/scifi (238,420 readers) Saturdays are “self-promo Saturdays,” so log in on Saturday to promote your book. If you look at the side bar you'll find numerous subreddits, and within those even more sub-subreddits.
r/sciencefiction (34,189 readers) This reddit is for fans and creators of science fiction and related media in any form.
SciFi Books – Community Board
Sci-Fi & Fantasy Books
Indie Authors and Self Published
For more detailed information about how you can make best use of Pinterest see: How to Use Pinterest to Build an Audience (For Writers)