Intermediaries, mediators and digital advertising's tensions

We argue that Latour’s distinction between ‘intermediaries’ and ‘mediators’ captures important facets of tensions in market encounters and in the co-creation of ‘supply’ and ‘demand’ within digital advertising. Drawing upon 110 interviews with 87 practitioners, participation in sector meetings and training courses, and McGowan’s ‘autoethnographic’ experiences, we explore the different forms tensions take in the two main configurations of digital advertising: 1) the ‘open marketplace’, which is the site of much effort to turn mediators into intermediaries; and 2) ‘walled gardens’, which increasingly are unequivocally mediators, and which are ‘de-agencing’ advertising’s human practitioners in specific ways (e.g. by making human-guided targeting less attractive and more difficult). De-agencing interacts with current initiatives, especially Apple’s, that partially ‘de-individualize’ advertising’s audiences and reinforce walled gardens’ mediator roles.