I have recently read some fantastic books with minor things off about their marketing. I want ALL of these gorgeous books to succeed, but I have limited time to advise on an author-by-author basis. So here's my quick-and-dirty advice, for anyone with a puzzling non-seller.

1) Spend as much time improving your covers/blurbs/ads as you do improving your writing. Look at other popular authors and learn from their marketing. Do you have a bolded first line in your blurb? Did you write a paragraph at the end mentioning the book's genre and tropes?

If the answer is no, and those are standard in your genre, GO FIX IT! Being indie rocks because you can change stuff every day. Covers are expensive, so if you don't have the money or skills to experiment, focus on your blurbs. It's free to tinker, and they affect sales.

2) Your first few pages (your book's preview) are also important and will often convince readers to buy and keep going. Work on punchy, interesting first lines, and make sure your first few pages immediately draw people in and make them want to read more.

3) Check your keywords and categories. See what the other books using those keywords/categories look like and read like. Are you aiming at the wrong readers? Even Jane Austen would have trouble marketing to horror readers, bc they don't want P&P, they want Stephen King.

I know some authors will tell you to put your book in as many maybe-possibly-relevant categories as possible, but DO NOT. For the love of god, if you're choosing cats on Amazon, choose ONLY relevant categories. You will otherwise mess with your data and destroy your ad relevance.

When choosing keywords, put yourself in the mindset of a reader who's in the mood for your book but doesn't yet know it. What might they actually type into the search engine? When your book shows up at the top of results, do they one-click it?

4) Run ads. They're not dirty, they're necessary. They also give you great data. Even if you're only spending a few dollars a day, you can check if your cover is good with impressions vs clicks and check if your blurb/preview is good with clicks vs sales.

I could probably go on all day, but I feel like these are the most basic tips I have.

(And now I go back to editing, which I am absolutely guilty of avoiding, fie on me.)