It's a great credibility builder too. Before you know it, everybody and their neighbor's dog will have your ebook. Create an ebook to give away free. Fill it with your affiliate links. You can also scatter banner ads throughout your ebook, but I'd recommend sticking with text links for the most part.
Some people see banner ads as an eye sore.
You can also take an ebook you charge money for, cut it down in size and give it away free. This will show prospects that you're a good writer and you give value. The net is full of freebie seekers and believe me, if you're giving it away they will take it. It's easy to feed the freebie seeker need. It's like they're hooked on freebies.