International audience—Major content/service providers are publishing grades they give to ISPs about the quality of delivery of their content. The goal is to inform customers about the " best " ISPs. But this could be an incentive for, or even a pressure on, ISPs to differentiate service and provide a better quality to those big content providers in order to be more attractive. This fits the network neutrality debate, but instead of the traditional vision of ISPs pressing content providers, we face here the opposite situation, still possibly at the expense of small content providers though. This paper designs a model describing the various actors and their strategies, analyzes it thanks to non-cooperative game theory, and quantifies the imp...