Most of the the entries on this list were discovered through my Twitter network. I am currently working on a novel, and I often look for services that promote new authors. I figured I'd pass on the research I've done, so without further ado, here's my list of new author and book promotion services and a little bit about them. (Don't have time to read? Watch the video on my YouTube Channel)
Buzz Bookstore
Buzz Bookstore is a different type of venue if you're looking for book promotions. The individual running this website mainly discovers and collects rare and vintage books, some even from the early 1800s and 1700s. Recently they've opened up a portal for the promotion of new authors. You can contact them through their website, and they're mainly looking for books that fit into their readership an audience. So keep in mind, that the audience that will be following Buzz Bookstore are individuals who are looking for old books, vintage books, rare books, and classics. I can't quite say exactly what their audience consists of, but I think it may be a fair guess to say that those in the historical novel genre or nonfiction genres may fit in.
Book Tweeters
Book Tweeters has a very fairly priced package variety for individuals trying to promote their books. The packages range of between $19 and $75, between one and five days of book promotion via tweets. Their main platform for promotion is Twitter, and they do not accept erotica books or books that include hate speeches or content.