Marketing certainly is hard, that's for sure. It takes time. It's best to start with who your target market is, before the book is written. With traditional publishing, authors write a book proposal and send it to a publisher. In that proposal, she includes market information (target reader, size of the audience, where they spend their time, and some thoughts on marketing to that audience). If the publisher likes the proposal, once the book is published, that marketing plan is laid out in more detail and they go to work. I recommend that self-publishers use a similar approach. Lay out your marketing before you write the book. Then, you can start marketing before the book is published, while you're still working on it. Prepare your audience for its release. Real successful self-publishers pre-sell the book, taking orders before it is released. That way, on launch date, your book has a better than even chances of landing on the best seller list (if you sell through Amazon).

Thanks for the great comment, and thanks for reading. Good luck with your publishing endeavors.