The practice of marketing has become increasingly technology-dependent, making organisations reliant on fragmented information systems that extend beyond organisational boundaries and requiring marketing workers to develop technology-related knowledge and/or collaborate more closely with those who have it. Despite massive investment in marketing technology, there has been little academic research on the intersection between marketing and technology knowledge. Drawing on three examples, we illustrate how complex and IS-dependent the practice of marketing and marketing decision-making have become. We then analyse those examples through the lens of knowledge management. Specifically, we consider the differences between traditional and modern marketing ecosystems and the implications for knowledge work, knowledge management, and decision-making at the level of organisations and ecosystems. We propose a provisional conceptual framework for understanding how market, marketing and technology knowledge have become intertwined and propose a research agenda for examining that more closely.