I worked at a hardware store...we would wave people who were holding a screw
or two out of line all the time. It's cheap "goodwill", and the person will
remmember it for awhile.

In retail if you do something nice for someone, they may tell their
wife....if you irritate them in the slightest way, they will tell anyone who
will listen about it for weeks! We always figured that if you did a
excellent job for the customer, 2-3 people heard about it....if you did a
good job, then 0-1 people heard about it....and if you fell down when they
visited, then 10-15 people heard about it.

It was like being Santa all year long, and people would feel like you gave
them a million dollars.