After buying and reading Cody Lindley's jQuery Enlightenment last year, I was so impressed with it that I asked Cody if he'd be willing to provide me with some discount codes to share on my blog. Expecting 25% off coupons or something similar, I was very surprised when he generously gave me 3 coupons for free copies of his popular book.
I don't usually buy technical books; I'm more of a hands-on learner and the books that I've purchased in the past just collect dust. It's one of the reasons why I'm so impressed with jQuery Enlightenment. Besides being an eBook (and therefore can't collect dust), Cody has structured the book in a way that makes it perfect to have as a learning tool as well as a reference.