The dominance of "ecosystem services" as a guiding concept for environmental management hides the fact that there are choices implicit in its framing and in its application. In other words, it is a highly political concept. In the Millennium Ecosystem Assessment (MEA), the concept of ecosystem services is presented as a neutral, obvious, taken-for-granted, and accepted by a consensus of the report's 1300 authors. By analyzing the MEA and case study examples from different tropical rain forest contexts, we show that different choices are required to define, measure, and value ecosystem services, all of which have ecological and political consequences. First, choices are made during the framing and institutionalization of the concept that mobilize, for example, a human-nature dichotomy and the pre-eminence of ecological and economic perspectives. Second, choices are made in the application of the concept, in terms of the type of 'service', the scale of analysis, and the kind of market rationality, that create winners and losers. Finally, choices are required when valuing different services - when for instance comparing different kinds of services provided by different kinds of natural and social processes at different scales. As a result, different interests use this 'buzzword' concept to justify different kinds of interventions that at times might be totally opposed. While it is theoretically possible to harness the notion of ecosystem services in ways that promote social justice, in practice it has largely served as a rhetorical and policy tool for biodiversity conservation interests.