The concept of service ecosystems emerged recently in service research as an important notion that underlines the complexity of structures in service interactions and the need for comprehensive approaches for the study of service systems. In this paper we focus on the role of the user as the ‘keystone entity’ of service ecosystems – especially for the creation of value. The research objective is to understand better the requirements and the implications of a user-centric perspective on service ecosystems and provide some basic modelling abstractions for the analysis of the structure and the objectives of the service ecosystem. Τhe paper develops the concept of the user-centric service ecosystem at the beginning and then provides a conceptual model of its structure and a goal model for the intentions of the actors. The paper can contribute to the better understanding of service ecosystems, the explanation of the role of the user and the fulfilment of the initial phases of requirements analysis for service ecosystems.