If Dan Ariely's previous book, "Predictably Irrational," were written by a self-help guru or a pop culture pundit, the concept that humans are both predictable and irrational might not be the most groundbreaking ever. But coming from a Duke University economist, this was a profound insight.
The context for this being surprising is, well, the fundamental doctrine underlying the academic field, which is that humans behave predictably and rationally, to maximize their best interests. Yeah, I know.
But the trick is that Ariely is a behavioral economist, so he spends a little more time than a traditional economist would exploring the psychological underpinnings of actual human economic behavior.