One of my earliest clients and very good friends (Edward Wright) once shared this gem of an image on Facebook. It is from Caltex of 1955 talking to "What is a Customer?".
Excusing the masculine wording of this and looking through to the concept of what is being said; it's very powerful and get's rave reviews.
Read it through, consider it deeply and many even print this out and stick it on their walls.
Enjoy and any questions please ask!