This is a classic video from Dan Pink which changes the way that you will see motivation. Dan Pink also wrote the book called Drive. Here are some tidbits from his book which sums up motivation:
When it comes to motivation, there’s a gap between what science knows and what business does. Our current business operating system–which is built around external, carrot-and-stick motivators–doesn’t work and often does harm. We need an upgrade. And science shows the way. This new approach has three critical elements: (1) Autonomy–the desire to direct our lives, (2) Mastery–the urge to get better and better at something that matters; and (3) Purpose–the yearning to do what we do in the service of something larger than ourselves.