If you're writing and planning to self-publish a book, don't overlook the need to publicize it for success. There's no doubt that the writing process was all-consuming, but your work also needs various book marketing services to succeed. In today's hyper-competitive marketplace, only well-marketed books have a fighting chance. When you plan a book publicity campaign, there are as many mistakes to avoid as there are good things to do. Believe it or not, many authors make mistakes that detract from the goal of having the book discovered by interested readers; it's vital to promote the book to the right audience.
First and most importantly, publicity must be targeted. For example, while a mention of your book on a hit show or in a widely read spot is nice, it only helps if the audience has a genuine interest. Many first-time authors become hung up on publicity in the most visible spots, regardless of the audience. What's most important is to focus strategically on publicity in places where the audience is interested in the book topic. Many times, specialized media with smaller audiences that are targeted can be more helpful to books and authors. It's wise to keep an open mind about publicity opportunities and look for value.
Every author today needs a professional, updated, well-designed website with helpful content. There was a time when having a site might have been an option; today, it's a requirement. It's where potential readers and the media will go first to find out more. Websites need an about page with your picture, a page about each book you've written, a media/press page, a contact page, links to social media, and a calendar of events page. If you're written several books, make sure to put the newest one (that you're trying to sell) in the most prominent position. It's also helpful to have a blog attached to the website.
Lastly, a word about social media: many people have outsized expectations about the role it can play in publicizing and selling copies of a book. Social media is valuable, and it has helped many authors. But it needs to be part of a broader marketing program (not the only tactic in use), and you must engage your followers – which means posting with appropriate frequency and content that people find interesting. Some authors are almost entirely focused on gaining new followers and overlook the need to engage with the current ones. It's easy for someone to click unfollow; don't be the one who people drop.