This chapter aims to identify the building blocks of a new way of conceptualising and measuring public service innovation. It is suggested that addressing public service innovation implies that a large number of heterogeneous players and of interactions among them is to be considered, hence making it particularly hard to identify a single (or a few) ‘representative subjects’ as units of analysis. Abandoning a pure subject-based approach poses important challenges to measurement and statistics. A possible way to tackle such challenges might be that of singling out a manageable variety of public services and of innovation types, including online services. This implies reversing the usual approach: from the identification of subjects as the key unit of observation leading to classify innovative activities correspondingly; to the identification of innovative objects leading to the identification of subjects involved in the generation and diffusion of such innovative objects.