Over at MarginalRevolution.com I offered free books — my new Discover Your Inner Economist: Use Incentives to Fall in Love, Survive Your Next Meeting, and Motivate Your Dentist -- to fifteen people who gave me good reasons for getting the book for free. They also had to vouch that these were reasons they truly believed in. You can read the reasons here, it is a fascinating series of arguments. One of my favorites is this:

I'm a graduate student in economics, and my funding is the sole source of income for my family (wife and daughter). My wife doesn't believe in the permanent income hypothesis, so I'm liquidity constrained. I'm searching for thesis ideas, and I think your book could be a great source.