A complete practitioner's treatment of United States advertising and marketing law for in-house counsel, agency lawyers, litigators, and regulators. Parts I through III cover the statutory architecture, the deception test drawn from the FTC's Deception Policy Statement, and the unfairness authority under Section 5(n) that now governs dark patterns and obstructed cancellation. Parts IV through VII cover the analytical core of the field: identifying express and implied claims from the net impression, the narrow scope of puffery, the prior substantiation doctrine and what competent and reliable scientific evidence requires, establishment and comparative claims, and the functional test for clear and conspicuous disclosure across media. Parts VIII through XIII cover the specialty regimes that generate most enforcement: the Endorsement Guides and influencer marketing, the consumer reviews rule, Made in USA and environmental and health claims, deceptive pricing and fees, negative option and auto-renewal marketing under ROSCA and the state statutes, and children's advertising. Part XIV maps the four enforcement forums and the remedies available in each after AMG Capital and Lexmark, including who besides the advertiser can be held liable. Part XV is a verification list for clearing a campaign or evaluating a claim.