The role of communication professionals, digital advertising firms and online campaign marketing companies has become crucial in internal party functioning, both during and between elections, which Dommett, Kefford and Power (2020) define as a "party-centred digital ecosystem". In this paper, we investigate the networks that parties establish with internal and external actors able to provide digital expertise and digital tools (companies, consultants, party staffers) for running not only digital campaigns and communication strategies (in particular through social networks), but also for running membership recruitment and participation, the selection of leaders and candidates, and overall party management. We will provide in particular a comparison between highly and less digitalized parties from the left in Spain and Italy (FSM, Podemos, PSOE, PD), based on the analysis of party internal documents and interviews with party officials.
