Remember, the 'customer' is always right. [=never argue with a customer]
He is one tough/tricky 'customer'. [=he is a tough/tricky person]
The company has good/poor 'customer' service.
(..) Well, then I'm afraid... I will be forced to go to your competition. I'm afraid they won't help you either. You see, in our line of work, a man has to present to the customer a convincing air of healthful vitality. Not to mention trustworthiness and incorruptibility. Please, please, please, please. (..)2014 TvShow: The Knick Title: The Golden Lotus Season: 1 Episode 9