Read this fantastic blog post by Tim Ferriss; book marketing guru, world traveler, and Author of The 4-Hour Workweek. Please pay special attention to the part where he mentions, “First off, writing books is a terrible revenue model for authors.”
His summary of the opportunities in eBook marketing are very clearly pointing to using affiliate marketing as the way to make that huge hit really happen. This is the important component that I see missing from almost every single plan that every Author has put in front of me, like, ever. If you want to make money from eBooks, learn every little thing you can about affiliate marketing, and then do it for a couple of years before you decide to get serious about the details.
I love this guy.