Collaborative innovation has led to the development of the concept of 'innovation networks' - defined as evolving systems of mutual dependency, based on resource relationships in which systemic character is the outcome of interactions, processes, procedures and institutionalization.When analyzing innovation on a collective level, concern regarding actors' heterogeneity and its effects on the innovation process emerges as relevant. However, in marketing studies, this topic has not been significantly developed.Innovation as a collective process involves a multitude of very heterogeneous business actors. Actors - such as companies, intermediaries, research centers, governmental institutions, trade unions, universities, laboratories, technology centers, development organizations, local and international associations - join together to achieve mutually defined goals. Hence the need for - and relevance of - this special two-part ebook, which is the first of its kind to examine innovation within b2b networks in two parts. Part one is entitled 'Innovation networks: the key role of actors' while the second is 'Organizing for innovation networks'. Together, the two parts provide a comprehensive resource for b2b innovation and cover:- Exploring the different sources of heterogeneity among actors- Exploring the various goals of actors in innovation networks- Mediating actors' heterogeneity- Dynamics of an innovation network- Business models in innovation networks- Coordination in innovation networks- Different types of innovation networks.