This paper addresses how network characteristics affect collaboration in open innovation applications. Combining insights from open innovation and networked innovation, this paper applies an analytical framework addressing the innovation process from ideation to potential innovation, with a focus on relationships between involved parties and types of collective action. The analysis is based on the use of an open innovation application in three organizations: a hospital, an IT-company and three municipalities. Findings suggest that open innovation applications for gathering ideas facilitate a cross-cutting of vertical/hierarchical and horizontal/domain boundaries yet do little to alleviate challenges with innovation-management and cross-domain communication. Innovation-work beyond ideation, proceeding from an idea to an implemented innovation, is an example of high level collaboration, requiring high levels of commitment, reciprocal trust, common purpose, mutual benefits and risks. The ideation-phase and the later phases of the innovation-process hence benefit from different constellations of networks.