A friend of mine has recently taught me a valuable lesson about motivation: you can incentivize people to take action, but the result may not necessarily be what you expect.
He used the example of his daughter and hockey. In order to motivate his daughter to try harder, he promised her an expensive reward if she scored a goal (she hadn't scored at all that season). The very next game, she scored a goal in the first five minutes, gave him a thumbs up... and stopped applying herself to the game. After all, she'd already achieved her goal of obtaining the expensive gift, so why bother?
Therein lies the danger of motivating our children, our employees, or even ourselves with external "carrots": the person we're trying to motivate with usually focus on the wrong goal.
Of course, some people are more externally motivated than others. Which one are you? Your Working Style Analysis will tell you.