1. A system for sharing consumer data among a plurality of entities, comprising: one or more computing devices configured to execute instructions that instruct the one or more computing devices to at least: receive, at a central marketing bureau system comprising one or more computing devices, first encrypted data from a first entity for a group of individuals and second encrypted data from a second entity for the group of individuals, wherein each respective individual in the group of individuals is associated with at least the first entity and the second entity, wherein the first encrypted data and the second encrypted data are encrypted using a forward encrypting hash algorithm to transform personally identifiable information associated with respective individuals of the group of individuals into anonymous identifiers associated with the respective individuals, wherein encryption of the first encrypted data and the second encrypted data occurs while the personally identifiable information is in volatile memory; append supplemental market segment data with the first encrypted data from the first entity and the second encrypted data from the second entity, wherein the respective individuals are associated with one or more market segments of the supplemental market segment data; and periodically transmit the appended market segment data, including the first encrypted data from the first entity and the second encrypted data from the second entity, to the first entity, wherein the first entity implements a first data appliance configured to generate an anonymized list of individuals based on matching of the appended market segment data to data associated with the group of individuals stored by the first entity, wherein the anonymized list is used to customize content provided by the first entity to one or more of the group of individuals.