Abstract: A method to be performed when a user is defining a target group for a marketing campaign includes receiving an input identifying an attribute value chosen by a user for determining which of several possible members to include in a target group. A first data repository contains data about each of the several possible members. The method includes determining whether the data that is associated with the attribute value has been loaded from the first data repository into a second data repository. If the data that is associated with the attribute value has been loaded into the second data repository, the method includes initiating a search in the second data repository with the attribute value to determine which of the several possible members to include in the target group. The second data repository may be configured to provide high-speed searching.