Phrases, quotes, songs, sayings, slogans and words have all been part of the marketing agenda for a long time.
Some get used to death, some are used rarely. All have a place in the marketing world. One of the more recent phrases that has been coined for marketing use is the Keep Calm and Carry On poster from WW2. This poster has been adapted into pretty much every way possible providing marketing material and branding collateral for businesses. There has also been a large number of posters created purely for comical value.
Below are some examples of the Keep Calm and Carry On poster used for marketing purposes: