Abstract: Disclosed herein are systems and methods of aggregating consumer data. The data may be acquired from numerous sources so that small portions of reliable data may be gathered into a single data set. Furthermore, by aggregating and analyzing such data, new insights and information about consumers may be discovered. Additionally disclosed are computer implemented arrangements for sharing of information that may provide incentives for data to be shared for purposes of aggregation and analysis. Some embodiments include a cooperative database system in which entities, such as marketers or communicators, may exchange data relating to consumers, such as email list activity data.