Abstract: Embodiments of the invention include systems and methods that enable the association and aggregation of consumer data gathered from online and offline sources. In particular, several embodiments are directed to linking consumer data in a data source controlled by an entity (e.g., such as a company's CRM (customer relationship management) database) to offline data sources such as demographic data, and/or online data sources such as online interaction data. The linking may be based on several identifiers (IDs) associated with the data sources. The systems and methods disclosed herein thus facilitate the association of these disparate data sources and enable various entities to better tailor interactions with the consumers. In other embodiments, a shared cookie data management system and method is disclosed. The shared cookie serves as a vehicle through which entities can selectively share consumer information with other entities in a system with uniform format and technical infrastructure.