Marketing agencies-in-common (MACs) have been used by farmer cooperatives for many years to accomplish specific marketing activities. Relatively scant attention or concern has been given to adequately defining MACs in terms of how they differ from other forms of organization, particularly from other federated cooperatives. Distinctions can be made in terms of the development and ownership of assets. Members of MACs retain individual member ownership of assets, with their MAC providing various supplementary functions such as group communications and product selling coordination. Members often have assets that are highly specific to their own marketing programs and have developed significant expertise in their respective industries. With a membership of this kind, MACs are governed in a multiple principal structure, in contrast to the usual generalized single principal-agent relationship that prevails in most cooperative forms of organization.