If you don't have time, return to the post later and learn from the most successful self-publisher I know of: JA Konrath, who says:
A virtual shelf, like Amazon or Smashwords, carries all my titles, all the time. And I don't have to compete with a NYT bestseller who has 400 copies of their latest hit on the shelf, while I only have one copy of mine. We each take up one virtual space per title. … Virtual shelf life is forever. In a bookstore, you have anywhere form a few weeks to a few months to sell your title, and then it gets returned. This is a big waste of money, and no incentive at all for the bookseller to move the book.