Living Labs provide a research infrastructure for long-term user involvement in Participatory Design processes. Users take part in software co-creation during context analysis, for concept development, reflecting on early-stage prototypes and evaluations in the field. In this paper we describe lessons learned from our Living Lab in the area of home entertainment, with 27 participants from 16 households, over a 2.5 year period. We show that this kind of long-term participation of users involves various challenges over the lifetime of the project. We highlight several aspects that need to be considered carefully when setting up such a Living Lab, concerning the selection of participants, maintenance of participants? motivation, establishment of a trust relationship, and the coordination of collaboration.