A common practice among servers in restaurants is to give their dining parties an unexpected gift in the form of candy when delivering the check. Two studies were conducted to evaluate the impact of this gesture on the tip percentages received by servers. Study 1 found that customers who received a small piece of chocolate along with the check tipped more than did customers who received no candy. Study 2 found that tips varied with the amount of the candy given to the customers as well as with the manner in which it was offered. It is argued that reciprocity is a stronger explanation for these findings than either impression management or the good mood effect.
Strohmetz, D. B., Rind, B., Fisher, R., & Lynn, M. (2002). Sweetening the till: The use of candy to increase restaurant tipping [Electronic version]. Retrieved [insert date], from Cornell University, School of Hospitality Administration site: http://scholarship.sha.cornell.edu/articles/130