An ad campaign involves a series of ads placed across various media to meet objectives based on analyzing marketing situations. The essential steps include: 1) assessing advertising opportunities, 2) analyzing the target market, 3) setting objectives like awareness, liking, or trial, 4) determining the budget, 5) deciding the media and creative strategy, 6) creating, pre-testing, and releasing ads, and 7) evaluating results through techniques like surveys, focus groups, and tracking studies.