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.
(..) the new John Grisham thriller ? Well, no, 'cause that's, uh-- that's a novel too, isn't it ? Oh, right. Have you got Winnie the Pooh ? Martin, your customer. Uh, can l help you ? Just, um, incidentally, uh, why... are you wearing that ? Combination of factors really. (..)1999 Notting Hill