This article found via Twitter is really great. It is always true that people pick out things that reinforce their own views, but hey… this matches my experience as well as my views:

How Rewards Can Backfire and Reduce Motivation | PsyBlog.

Motivation has to be so much more than carrots and sticks… In fact, the best way to motivate people in my view is to find self motivated people and then hire… taking unmotivated people and making them motivated is really difficult.