The process of enhancing existing subscriber data by adding additional information from various sources to provide a more comprehensive view of each individual. This involves supplementing basic contact details with demographic, behavioral, and psychographic data, as well as updating and verifying contact information.

By integrating internal and external data sources, such as social media and third-party databases, data enrichment allows marketers to create more targeted and personalized email campaigns. This improved data quality facilitates precise audience segmentation, leading to more relevant communications, higher engagement rates, and better decision-making.