Some employees work harder when rewarded with personalized gifts as opposed to monetary raises.
According to Slate, a study on gift exchange in the work place shows that gifts are more effective than one might expect.
The study focused on a group of students helping to catalog books in a German university library who were paid the same general stipend and offered a raise, while others were offered a water bottle in addition to the wage.
The cash bonus didn't have any effect on the speed or accuracy with which the students did their jobs. However, those receiving the free bottle reciprocated by upping their data-entry rate by 25 percent, a productivity increase that more than offset the cost of the bottle itself.
Though this method worked in this scenario, it may not be so efficient in all fields of work, for cash can be a stronger motivator in more serious situations.