It has been fun here in France to observe how it is different from America, and from my time in England. One thing that has really struck me is that the onus is on the customer to provide the tenor of the interaction here. They call it simply "politesse", but from what I've observed, it is my job to say "Bonjour" first, preferably "Bonjour madame". I then have free license to ask for whatever I want. When the transaction is complete I must say "Merci, au revoir!", perferably in an upbeat sing-song voice. Failure to comply with these rules has resulted in lousy service. Smiling has helped.
I know we're all angels of light and cheer when we're out shopping at JoAnn's-Handcock-Wlamart, but perhaps the customers before you are scowling and blaming the clerk for the poor quality of the fleece, etc.
We're all humans! There are good days and bad days and brain-dead people who don't care.
-Charlotte