FreeBooksy is a promo service owned by Written Word Media, that also houses Bargain Booksy, and newer sites Red Feather Romance and NewInBooks. FreeBooksy is designed to promote books that are either permafree or temporarily free through KDP. They have over 230,000 registered readers with a voracious appetite for books.
If you are planning to discount your book (or if your book is already priced between $0.99 and $5), the Bargain Booksy Feature is for you. With over 170,000 registered users a Bargain Booksy feature can help you to drive sales of your book, find a new audience of readers, generate reviews for your book, and improve your book rank on retail sites.
Awesomegang offers both free submissions and paid listings.
Besides the 2 day Featured Listing mentioned above books also get put in their newsletters which are mailed daily to readers looking for books.
As a bonus they send out links to books on their social media accounts. They guarantee it once a day but it is usually twice a day unless they get a lot of book submissions.
BookBub is a book marketing and discovery platform that promotes limited-time discounts on ebooks. Readers sign up to receive a daily email alerting them to deals in categories that match their interests, while authors, publishers, and agents partner with them to reach the millions of book lovers who use their service.
James H. Mayfield social media promo service can be considered a Virtual Assistant service. The promo involves posting ads to the authors book, during promotional days, on several different social media sites, including Facebook, Reddit, Twitter, as well as various Forums and Sites.