To help support fellow authors, I like to boost books in my newsletter, and it's completely free! There's just a couple rules:
Your book must be finished and available for order or pre-order. Or, if you are doing a Kickstarter, you must have a pre-launch page up or the Kickstarter actively running.
The book must have a good quality cover. This doesn't mean that you need to pay a professional to do it! It just means that the text needs to be legible, you need to have the rights to all imagery used in the cover, the image quality needs to be good, and it has to have been made by a human (no AI covers allowed).
If you'd like to be featured, head to the form at the bottom of this page and fill it out. I'll add you to my next newsletter. Newsletters tend to go out at least once every 1-2 months.