I have been looking forward to this post. This is a GREAT idea, but I can't take credit for it. I found it online while looking for new ideas. Once in a while I put something like 'Marketing Ideas' or 'Marketing Ebooks' in the search engine. I've found a few interesting things while doing this. Here is one of them.
When you are ready to release a book, find someone else releasing a book at around the same time. Then trade a first scene or first chapter with them. Paste their excerpt on the end of your book as an added bonus for your readers. The other author will do the same for you. Then you reach a larger audience. When someone buys your book, they will be able to try out a sample of the other author's work. Likewise, people who read their book will get to sample yours. I just tried this a couple of months ago. It's too early to tell if it's helped me, but I know it hasn't hurt me.
Anyway, I thought this was an awesome idea and worth a try. :)