Managers need to actively drive the growth of innovation ecosystems. This paper describes the obstacles companies face when commercializing innovations and identifies strategies for overcoming these barriers through activating innovation ecosystems. We explore three ecosystems at different stages of maturity, namely San Francisco, Barcelona, and Nairobi, and derive a taxonomy of strategies for activating innovation ecosystems with regard to the maturity of the ecosystem. The paper thus contributes to the wealth of knowledge concerning the commercialization of innovations in general and within innovation ecosystems in particular. We fill a gap in the understanding of the stages of maturity of innovation ecosystems, and the corresponding actions required by managers and policy makers. Policy makers and other actors can incentivize ecosystem development through adapting initiatives to the maturity of the ecosystem in question.