This study investigated the networked relationships between agency parties involved in the process of advertising planning, internal and external to advertising agencies. The study provides a conceptual grounding for understanding the shift from dyadic to multiple relationships in advertising planning. It focuses on the degree of collaboration and integrative relationships inherent. Using a theoretically derived, grounded theory approach, depth interviews were conducted with twenty two practitioners spread across four dominant parties: advertising account management and creatives, independent media planners and researchers. Four core constructs were abstracted from the data forming the conceptual basis for a model. These were shared (agency) purpose and philosophy, personal chemistry between involved parties, power relations between parties with their incumbent conflictual tensions and finally trust between parties. The study provides an important bridgehead, opening up and exploring the increasingly networked foundations for advertising planning.