Since the mid-1990s, the concept of ecosystem services has become increasingly popular, in academic circles and among decision makers. Because of its inclusive character, this concept has given rise to different interpretations in economics. Since its inception, it has been associated with the development of market-based instruments (MBIs) in conservation policies. From this perspective, the sustainable provision of ecosystem services is hindered by market failures (e.g., public good attributes, externalities) and prices that do not capture the full value of the natural assets. MBIs are therefore recommended. According to their promoters, they provide powerful incentives to conserve the environment, while at the same time offering new sources of income to support rural livelihoods. Our paper contends that different economic narratives, and associated representations of the market failure at stake with the provision of ecosystem services, may support different policy instruments that are all coined as MBIs. As an illustration, we analyse the economic discourse underlying payments for ecosystem services and eco-labels, and we underline the variety of institutional forms to which they give rise in order to emphasize the differences between discourse and practice.