As an indie author one of the greatest challenges you will face occurs not when you are writing your book, but once the work is published. The writing, editing, proofreading, artwork design and publishing parts are all easy when compared to trying to make your work known to potential readers.
Books are not sold in the way that other consumer goods are sold. Rarely will you be able to convince someone they need to buy and read your book. The only possible exception to this is if you are publishing a non-fiction work and are a known expert on the topic of your book. Think about it: when was the last time someone walked up to you with a book, told you what it was about and then you purchased it? Never, right?
Most books are "discovered" and the decision to purchase the book is made after reading a few pages which catch the interest of the reader. Other books are sold based on recommendations made by friends or co-workers, or through book reviews.
In the world of the indie author, it is not good enough just to write a good book, have an excellent, eye-catching cover and then publish it online and hope for the best. There are literally millions of ebooks and paperbacks published on Amazon alone, so your book will probably quickly become lost in the pile.
So how do you make people aware of your masterpiece? You need to advertise. Now there are a LOT of businesses and people online that target indie authors and are more than willing to help you part with your hard-earned money. From my research and personal experience, most paid advertising brings little in the way of returns. Companies that offer to promote your book to thousands, or hundreds of thousands of people, will most likely just mention your book in an email blast or tweet. I like to call this the "shotgun" approach which may or may not result in any reasonable quantity of sales.
So what is the best way for an indie author to make sales? Unless you have unlimited funds for advertising, which most of us do not, there are several things you can do:
1) Give free copies of your books to local book clubs. If you have written a good book, word of mouth will help sell copies and develop a fan base.
2) Set up a Facebook page and post "teasers" from your story for potential readers to discover. You can also post updates on new stories.
3) Open a Twitter account separate from your personal account, and follow other authors and post interesting tweets in order to garner interested followers. Do not only send tweets asking people to buy your book though, that is a quick way to be unfollowed. Instead, post updates, special sales, links to articles about your book and free previews.
4) Start an author webpage. This one is a must in order to establish your credibility as an author. Your books should be posted, along with links where readers can purchase them, but should also contain some interesting information about you, the author. Include a biography and tell your readers what motivates you as an author. Make sure you add a form for interested parties to sign up for updates and from this you can generate an email marketing list.
5) Start a blog. A blog is a fun way to practice your writing skills and also let potential and existing readers learn about your writing style. Do not use the blog only to try and sell your books though, include helpful information for readers that they will find of interest.
6) Use pay per click advertising on Amazon. Most indie authors use Amazon as a primary sales channel for their books, and Amazon has millions of paying customers looking for e-books, so using Amazon to make those customers aware of your work makes sense. However, you can quickly spend hundreds of dollars or more if you don't use the Amazon pay per click correctly. I have found that the most effective advertising is their manually targeted ppc ads set with a maximum daily spend. I use $5.00 per day as my maximum and once that is reached (which rarely happens), your ads are paused until the following day. In the meantime your book will be placed where interested parties can see it, often thousands of times. Since a book ad generally has to be seen by someone several times before they click on the ad and investigate it, you are putting your books in front of thousands of potential readers and only paying when someone clicks on the ad. The cost per click can be set by the advertiser and usually starts at $0.25 per click, depending on the key word popularity. Choose your key words carefully and increase the amount per click to $0.50 which should guarantee you more postings (called impressions) than at the $0.25 level. On the Amazon author boards I see a lot of indie's complaining about the lack of ad impressions, but I have found raising the cost per click rate greatly improves my impressions, and with a $5.00 daily limit, does not increase my costs.
There are also a number of "free" websites where you can advertise your books but do not all guarantee placement of your ad. To guarantee your ad will be placed, most require a fee. Use the free service - it will take some time to post on each of the free websites, but you have nothing to lose and everything to gain.
Above all else remember that books are not fresh bread - they don't go stale. Selling books is a marathon, not a sprint, and building your reputation as an author will take time. Don't ignore the importance of advertising, but don't spend all of your time and money doing it. Instead, continue to work on your craft. If you have written a good book with an interesting story, the sales will come.