Smart cities all around the world are reimagining their future with technology as the new normal. At the same time different definitions abound about what being smart actually means. In order to make the distinction between which projects are mere digital “pixie dust” and which ones will truly reshape the urban future, a better framing is necessary. Ecosystems are a key part to frame which elements will be important in realising truly smart cities. A truly smart city will be that city that succeeds in understanding, activating, orchestrating, servicing and reinventing the complex ecosystems it consists of. In the long run the active management of ecosystems will be more decisive for smart city ambition success than vision, political commitment or technological ability.