Never write an advertisement which you wouldn't want your family to read. You wouldn't tell lies to your own wife. Don't tell them to mine.
Source: In Quotable Business, ed. Louis E. Boone, 1992.
-- David Ogilvy, (Jun 23 1911-1999), US advertising executive; He founded Ogilvy & Mather advertising agency and created the Hathaway eyepatch man.