AI has disrupted the traditional certainty paradigm of advertising, which has historically focused on capturing attention. This paper examines the characteristics of the certainty paradigm in AI advertising, based on the impact of AI on advertising activities. It firstly proposes five stages of the certainty paradigm throughout the evolution of advertising: the uncertainty of the “product” searching for the “consumer” in the natural media era, the certainty of the “product” searching for the “consumer” in the mass media era, the certainty of the “consumer” searching for the “product” in the early internet era, the certainty of the “product” searching for the “consumer” in the early programmatic advertising era, and the certainty of the “consumer” leveraging the virtual-real world to serve themselves in the AI era. Then it further explores the fundamental mechanisms of certainty paradigm in AI advertising. Certainty is determined by the temporal, spatial, interactive, sensory, interoperable, and transparent dimensions of media technologies. The key characteristics of certainty are temporal immediacy, spatial three-dimensionality, intelligent reasoning, and ecological consumption. The aim of certainty is to achieve better return on investment among consumers, advertisers, and intelligent platforms ultimately. The “consumer-product-scene” is reconstructed through generated intelligence between “consumer-product”, embodied intelligence between “consumer-scene”, and IoT intelligence between “product-scene”. As a result, consumers can continuously pursue the certainty of their needs through intelligent interactions among the “consumer-product-scene”.