It is widely recognized that the concept of service innovation is significant for innovation strategy and economic growth. However, since the term service innovation represents a broad sense, there does not exist common understanding about what is service innovation even among experts. We developed a methodology to determine the structure and geographical distribution of knowledge, as well as to reveal the structure of research collaboration in such an interdisciplinary area as service innovation, by performing journal information analysis, network analysis and visualization. Our results show that there are mainly two groups of elements relating to service innovation. Knowledge in these areas has been growing rapidly in recent years. In particular, the fields of ecosystem and IT and Web are exhibiting a high growth. We also demonstrated that the global network of knowledge is formed around the powerful hub of the US. The research competency of Asian countries lags behind that of the US and EU. With respect to research collaboration, we indentify a big room left for enhancing international collaborations. Our methodology could be useful in forming policies to promote service innovation. Finally, we proposed creation of an international collaboration fund.