If you have not heard of Jane Friendman, you need to visit her website and blog. She is a wealth of information on book promotion and the publishing industry (traditional and indie). I recently had the pleasure of hearing her speak at the Virginia Romance Writers' meeting in Central Virginia.
Here's what I learned from her about book promotion.
1. Your book cover is key. It must fit your genre. If you're writing a series, the books need to look like they're in the same family.
2. Check out the BookBub blog. It contains a lot of good information for authors.
3. The description of your book on the book cover should be your hook. It should be short with multiple paragraphs. Make it easy to read.
4. Look at your book's description on Amazon. Your key information should be above the "read more" link.
5. If you're looking for keywords in your genre, find a similar book to yours on Goodreads. Select the book. Then look over on the right for the See Top Shelves link. This shows you the search words that people used for this work.
6. Make sure you have a biography and headshot for your Amazon author account (and that they are current). Claim all of your books, link all of your social media, and attach your blog to this account.
7. When you're coming up with your description and keywords, think like a reader. She gave an example of an author who described her books in a unique way. But the terminology wasn't standard, and her books weren't appearing in searches. Friedman recommended to Google the term to see if it comes back in a standard search.
8. There are two types of Amazon ads, sponsored products and product displays. Read Amazon's advertising information for details of each and to see what best fits your marketing campaign.
Check out Friedman's blog and newsletters. The information is invaluable to authors.