Digital assistant ecosystems such as Amazon Alexa and Google Assistant are growing at a fever pitch, and an ever-expanding list of compatible devices and services is helping smart home device manufacturers and service providers reach more customers than ever. It is no longer a question of whether these companies are part of a digital assistant ecosystem, but to what extent. The rules of engagement between these companies and ecosystems are changing as growth accelerates, highlighting areas of opportunity – and caution – for device manufacturers, service providers, and digital assistant platforms alike.