The online advertising ecosystem’s reliance on consumer behavioral tracking creates an intense, unresolved debate over the impact of online ads on consumer shopping behavior, outcomes, and satisfaction. Existing empirical work has been helpful, but identifying the causal effects of ad exposure separately from behavioral targeting across the advertising ecosystem, and the potential impact of privacy technologies on that ecosystem, presents methodological challenges. This Registered Report presents a large-scale, ecosystem-wide, randomized, three-condition longitudinal field experiment. Participants are assigned to (1) Targeted Ads, (2) Anti-tracking, or (3) Ad-blocking conditions, and both observational and survey data are collected over a three month period. This design estimates the incremental effect of targeting and allows for a causal test of three competing macro-theories that predate the digital age: the Informative Engine (Nelson 1974), the Market-Shuffling and User Experience Engine (Dixit and Norman 1978), and the Complementary View/Peripheral Influence Engine (Hansen and Christensen 2003). This field experiment provides an ecosystem-wide assessment of the causal impact of online advertising on consumer purchasing behavior, outcomes, and satisfaction.