It doesn't matter if you're an indie author or traditional author, it's mainly the author's responsibility to spearhead book promotion. There are various ways this can be done; most notably the word of mouth. This is usually done via book signing, radio or television guest appearances, or book reviews in newspapers or magazines. These tried-and-true methods can be very expensive, and authors with limited budgets have trouble getting the word out about his or her book. Amazon’s platform has made it very easy to publish a book, and Kindle Direct Publishing Select (KDP Select) has leveled the playing field in terms of bridging the gap between paperback sales and ebook sales.
Online marketing has given me mixed results so far—I achieved low to moderate sales using Twitter, Facebook or author-friendly sites like Goodreads and AuthorsDen; but those methods were time-consuming and tedious and take away from writing time. I've also found that offering a free promotion of my books on Amazon Kindle for a short period of time (usually one or two days) has given me a short spike in sales before bottoming out rather quickly. I have coupled that with setting my ebook prices as low as Amazon would allow ($0.99) in order to sell as many copies as possible.
Creating a high-traffic website or blog will undoubtedly increase sales, but the ever-changing Google algorithm has made this an extremely arduous task. A blog or website won't survive without a steady stream of visitors, and this can only be achieved by creating relevant back links. More back links will increase the page rank; and this will send more traffic to a website or blog from the top search engines like Google, MSN, and Yahoo. Pay-per-click advertising is another way to increase book sales, and Google and Facebook are two sites that will allow a marketer to create a campaign suited for any size advertising budget. However, I’ve discovered that maintaining an effective advertising campaign on Google or Facebook is too expensive for my advertising budget.
No method is more effective than garnering positive reviews for your book. Positive reviews on Amazon will boost sales exponentially, and I’ve seen many authors sales rank go through the roof because of this. Getting positive reviews has also been a challenge for me, but so have the other methods of book promotion. Amazon is cracking down on fake reviews as a means of boosting sales, so the best way to receive positive reviews for me is to write a good book. The book race is a marathon, not a sprint, and I’ve come to the conclusion that it’s better for me to keep putting out quality books and build a slow but steady following of my work.