member of a decision-making unit or social group who acts to prevent or discourage a purchase by controlling the flow of information and/or access to people in the buying center. A mother who does not allow her child to choose a presweetened cereal at the supermarket is acting as a gatekeeper. A secretary who does not put calls through to the decision maker is a gatekeeper. Marketers must direct their advertisements not only to the end user, but also to any potential gatekeepers.