In marketing, particularly in online advertising, the concept of probabilistic data refers to a method of identifying a person based on a probability model rather than on an identifier considered infallible due to its uniqueness. Unlike identification by a machine identifier (the deterministic approach), recognizing an individual can rely on a specific combination deduced from their software environment and parameters observed on their smartphone or computer. Probabilistic data is often considered slightly less reliable than deterministic data in consumer targeting strategies related to digital marketing practices.