We present in this article a flexible management system for dynamic placement of content replicas. It is able to satisfy users' constraints and preferences, while limiting the load of servers and proxy-caches. Our goal is to optimize the placement in order to lower the number of replicas while keeping the best end-user QoS. Our proposal is based on local decision mechanisms of duplication and migration in a P2P way. Our system allows owners to keep the control over their contents even in the context of large scale replica dissemination. Experiments with real web traces validate the approach.