The rhetoric of open government data (OGD) promises that data transparency will lead to multiple public benefits: economic and social innovation, civic participation, public-private collaboration, and public accountability. In reality much less has been accomplished in practice than advocates have hoped. OGD research to address this gap tends to fall into two streams – one that focuses on data publication and re-use for purposes of innovation, and one that views publication as a stimulus for civic participation and government accountability - with little attention to whether or how these two views interact. In this paper we use an ecosystem perspective to explore this question. Through an exploratory case study we show how two related cycles of influences can flow from open data publication. The first addresses transparency for innovation goals, the second addresses larger issues of data use for public engagement and greater government accountability. Together they help explain the potential and also the barriers to reaching both kinds of goals.