Abstract (EN)

Multi-sided platforms, enabling interactions between different user sides, hold an important place in the contemporary economy. Current literature, focusing on established and successful platforms, has neglected to study B2B multi-sided platform adoption mechanisms. In this article, we analyze these mechanisms by investigating the case of dematerialization platforms for B2B transactions between the multiple actors involved in public works contracts. Various qualitative materials, including 28 semi-structured interviews, were gathered over a thirty-month period. Adopting a business user perspective, this study contributes to the literature on multi-sided platforms in various ways. We show that platform adoption, in project-based B2B contexts, is mainly constrained by a high level of affiliation costs and the existence of tight-interdependencies between users' activities at project level. Thus, a consecutive adoption path would result in negative cross-group network externalities and undermine the platform's attractiveness. Conversely, a concurrent adoption path would activate positive network externalities and encourage platform adoption decisions.