This book was somewhat entertaining, but I can't really recommend it. The author does experiments with college students and beer, and extrapolates this into a world view. Most of his applications are anecdotal.
Here's an example on p. 215: "Iran is another example of a nation stricken by distrust. An Iranian student at MIT told me that business there lacks a platform of trust. Because of this, no one pays in advance, no one offers credit, and no one is willing to take risks. People must hire within their families, where some level of trust exists. Would you like to live in such a world?" Excuse me, but I prefer to base my world view on more than just the impressions of 1 college student, but this is an example of how he doesn't use logic to come to his conclusions. Here's another tidbit on p. 218 "...drug companies cheat by sending doctors and their wives off on posh vacations." Using Ariely's logic, this means that all doctors are male, or the women doctors are all lesbians with wives. His experiments on cheating have flaws. Since the "cheating" group scored more than the "non-cheating" group, the cheating group MUST have cheated; but they were allowed to destroy their answer sheets. There is no proof that this group cheated; they could have just come from a higher level class, or had more coffee.
Did you notice how he leads you to the conclusions he wants you to reach? Would an objective researcher characterize one of his subjects as "a clever master's student with a charming Indian accent?" Wouldn't you be more likely to agree with the conclusion than if the participant was a "clever hunchback with an aversion to bathing?" He ascribes all kinds of emotions to his subjects throughout the book. It's not that it isn't worth a read - just realize he's working on your predictability to lead you to his conclusions.