Psychologists have believed this for years. We tend to take for granted and not appreciate the thing that has become routine. There is a certain excitement factor in something we cannot take for granted or assume. Psychologists have taught us that the intensity and duration of a given motivator are enhanced if the reward is immediately given following the act or behavior. This immediate reinforcement leaves no confusion in the mind of the performer what the reward is for.
People are very complex creatures.
Every individual has a different history and a unique set of values and needs. What might ordinarily be perceived as a reward by one person may be viewed as having little value or even as a punishment by another. Furthermore, the higher the value the recipient of the reward places on the successful completion of the behavior that is being rewarded, the more powerful and personally rewarding it is. Context is the time, the place and the way the reward is delivered. Context is partly a matter of the culture of a particular organization.