For an unknown author like me, I can attest that a combination of free and sales is a great strategy. Making 9k isn't bad for a book.
I've been doing something similar with my novel, Betrayal. I am releasing the whole book, a chapter at a time, with a link to Smashwords.com, where I have it for sale ($.99). Before I started giving the book away, I had less than 10 sales. On Smashwords, the first 20% was available for free, but I still didn't see the sales.
However, once I started posting more free chapters, I've had 50 sales a week! Not sure how sales will hold up once I finish releasing the whole thing, but I am hoping for a result similar to this guys experience. With a
.99 sale price, I have been getting enough reviews and sales to make it onto the sales charts at Smashwords.
The main point is that without giving it away for free, no one would have ever heard of me. I would have made fewer sales by only giving away a small portion, than I am by giving away the whole book.