This study addresses a gap in the extensive scholarly literature on advertising humor by exploring advertisers’ uses of humor and explanations for its broad appeal as a message tactic throughout the previous century. The study’s sources consist mainly of articles published in the important advertising trade journal Printers’ Ink, supplemented with more recent articles from contemporary marketing and advertising trade journals. An examination of the evolution of professional thought regarding humor indicates that its use during various periods often represented a response to perceptions of changing societal factors and the consequential need to attract greater attention to advertising, the more frequent use of emotional versus rational appeals, the belief that advertising should entertain, changing perceptions of the role of advertising, and the content of the entertainment media.