In the future of Ancillary Services for the HV grid, Demand Side Response (DSR) will play an increasingly important role to ensure grid stability and promote Renewable Energy Sources integration in the electrical system. A particular use case of the Italian Demo of the H2020 project “Optimal System-Mix Of flexibility Solutions for European electricity” (OSMOSE) is to demonstrate multiple grid services provision based on DSR by seven industrial plants distributed in a HV grid area between Apulia and Basilicata. Sites have been managed by three Balance Service Providers (BSPs). On each industrial plant, project partners first have performed an energy audit and then they have installed all the electric and TLC equipment needed to test and manage the flexibilities identified. The main result of these activities was that the hardware required for DSR comes at a relatively small price compared to the magnitude of loads that could be controlled. Purpose of this work is to provide an analysis of possible benefits and limits of DSR for the grid as well as to direct a possible new future market strategy for these resources.