Engaging MV and LV end-users in providing ancillary services to the main grid is a very interesting scenario, in which the traditional interactions between Distribution System Operators and customers are significantly modified. In this work, a novel pricing structure is introduced to investigate how the behaviour of active end-users, including local generation and storage systems, could be influenced. In particular, suitably modifying the unit price of electricity according to the power exchanged at the connection node, a double benefit is directly achievable: on one hand, a substantial reduction of the customer billing cost is possible by optimally sizing and managing a local storage system; on the other hand, from the Distribution System Operator's perspective, the modified end-users behaviour facilitates the network management, since voltage violations and line congestions become less frequent. As a result, without increasing the end-users' costs, the proposed approach is able to opportunely influence their power profiles and to indirectly increase the network hosting capacity