Most people will say no but that mint can make a surprising difference in the study giving diners a single mint at the end of their meal typically increased tips by around three percent interestingly if the gift is doubled and two mints are provided tips don't double, they quadruple a 14 percent increase in tips but perhaps most interestingly of all is the fact that if the waiter provides one mint starts to walk away from the table but pauses, turns back, and says "for you nice people, here's an extra mint" tips go through the roof a 23 percent increase influence not by what was given but how it was given so the key to using the principle of reciprocation is to be the first to give and to ensure that what you give is personalized and unexpected.