What the real secret of being successful as an indie author? Sticking with it. The key ingredient to success at anything is perserverence. You have to learn how to stick with it...even when the entire universe is conspiring against you in every possible way.
Success and stubbornness go hand-in-hand. People who are successful heard the word "no" hundreds of times before getting the "yes" that mattered. If you want to make it as an indie author, you've got to stick with it. Cement yourself to a spot, hitch your wagon to a goal, and don't waver.
If you want to get more readers and sell more books, you have to work at it. Readers for indie authors often come slowly, one at a time. You've got to use your stubbornness in order keep getting them. Keep maintaining your blog. Post fresh content, keep building up that archive of posts, and slowly regular followers will trickle in. Keep working on your Twitter and social media accounts. Keep following people, keep posting updates and keep staying active to continue gaining new readers.
You may have to work at it for years and years before you ever see real results, but that's the nature of being an indie author. You didn't give up on getting your books published, so give up on getting them read. Keep working at it and you will build up a fan base, over time. You will sell books to people who want to read them.
But while you're building your base, don't forget to work on your craft. Continue building yourself as an author, and make each new book better than the last.