"Guilt issues aside, research has shown that the quality of the service we receive isn't always reflected in the tip we leave. Many who have studied the practice have discovered that excellent service only draws a marginally higher tip than average service. Other things the server might do, however, do make more of a difference -- probably without our even realizing it! For example, Cornell University's Center for Hospitality Research has conducted several studies revealing some interesting facts about server habits that can boost tip percentages. Here are a few of them."

How tipping works.