I&#x27;d like to share some anecdotes from my experiences as a waiter.<p>1. The people who demand the most service (&quot;This is too cold, take it back&quot;, &quot;Bring me a different fork, this one has a spot on it&quot;, etc) tip significantly below average, and sometimes not at all.  This pattern is present just about everywhere- I see it in IT all the time.<p>2. Groups, especially business meetings, are the highest tippers.  Serving a table of 8 isn&#x27;t significantly harder than serving a table of 2, yet groups usually still tip based on percentage.<p>3. People who use coupons are universally small tippers.  I also suspect that folks with coupons are not likely to be return customers.