If you don't know him, you should. Scott Sigler is an "open-source" author who heard about this "podcasting thing" and just happened to have a finished book lying around. Sigler is arguably the father of serial podcast fiction, attempting to emulate the serial nature of radio stories from the 40's in this new format.
His fans are fanatical about his work, and even though he gives away his books as free audio podcasts and PDF's, his books still sell really well. Sigler believes this new model of try-before-you-buy is the future, and he is certainly at the front of it.
Last year Crown Publishing, a large publisher saw that his open-source model was working very well and decided to give it a chance. On April 1st 2008 Sigler's Infected was released and just barely missed the NY Times best-seller list.
Below is the trailer for Infected, and as a huge fan of his work I encourage everyone to buy it. The idea being that if Sigler can sell more books, he can turn this into his full-time job, and full-time means more free podcasts and books. On the other hand, if you aren't ready to buy his book, then try-before-you-buy by visiting his website and listening to his books for free.