While some argue that innovation is inhibited by installed base, this paper suggests that it is critical to service innovation. In particular, the installed base of devices and infrastructure is an important element for improved diffusion and higher acceptance of services. It brings forward a nuanced view of installed base and reports a case study of Swedish National Road Administration's strategy for increasing safety on the roads with intelligent speed adaptation (ISA) services. Over time, they changed the strategy in order to employ existing installed base available.