Marshall McLuhan, Understanding Media: The extensions of man, 1964

An expensive ad represents the toil, attention, testing, wit, art, and skill of many people. Far more thought and care go into the composition of any prominent ad in a newspaper or magazine than go into the writing of their features and editorials. Any expensive ad is as carefully built on the tested foundations of public stereotypes or 'sets' of established attitudes, as any skyscraper is built on bedrock.