The Encyclopedia of Major Marketing Campaigns looks at 500 major marketing and advertising campaigns of the 20th century from a historical perspective and several related initiatives of earlier years that developed the basis for present day advertising.

Entry articles, averaging 2,000 words in length, look at the advertising campaign's or market initiative's historical context, target market, expected outcomes, competition, marketing strategy and development hurdles and the outcome of the campaign — what worked, what didn't and why. The entry ends with further information for researchers — references to competitors and annotated citations to relevant campaigns and periodical articles.