In the last decade, the foundations of the digital economy have been formed with Internet platforms becoming its largest and most important segment. According to the authors, one of the key problems associated with the development of the digital economy and of Internet platforms is the diffusion of existing and generation of the new competencies. This is important both for platform users and partner companies. The article analyzes the role of platforms in this process and highlights the main channels for competence diffusion. Firstly, individual and, secondly, institutional dimensions of these processes are defined. In the first case, the authors elaborate on the ways of developing user competencies - both basic and specialized. In the second case, the article focuses  on the distribution of organizational and institutional competencies, and best practices among partner companies and participants in corporate ecosystems of platforms. For the partners the primary conditions for acquiring new competencies depend, firstly, on a system of organizational and economic requirements of the platforms. Secondly — on specific digital interfaces. Growth and improvement of services, technology, dynamics and principles of platform market organization provide formation and diffusion of more complex economic and technical competences of digital economy. It is shown that a new powerful source of development and transfer of promising technological and economic competences within the extended platform ecosystems is also being formed. The scope of operations of modern digital platforms, their composition, engagement of all key groups of actors in the innovation processes (including consumers) create unique opportunities for further development of this area.