A recent survey of author incomes showed that 80% of self published authors earn less than $1000 per year. In most cases, it's because readers haven't heard of the authors (no exposure), they didn't know the book existed (no visibility), or they've overlooked the book because of poor cover design and poorly written blurb.  

Don’t become ONE of those authors, especially if you’re self-published and don’t have the distribution to bookstores and libraries like the big publishers have. Find resources here to promote your books to new readers, and discover publication services to create the best quality book and promotional material to give your product the best chance of selling.