Measuring the true incremental impact of media spend remains one of the toughest problems in marketing, especially in an era where privacy limits user-level tracking. This talk examines how geo-lift incrementality testing can be utilized to accurately measure the true causal impact of marketing and media channels. Attendees will learn what design decisions matter, how to analyze results, and common pitfalls to avoid when running marketing incrementality tests. The goal is to bring causal inference theory into real-world measurement, enabling practitioners to make informed, data-driven decisions with confidence.