I have a neighbour who lives on her own, is very careful about what she does and only uses her bin once every four weeks. In our house we fill it every week and pay for it. By reducing their use of the service, people should be able to reduce the amount they pay. This system allows us to put a brake on the extent to which services are drawn on. If a service is free, users have no incentive to restrict their use of it. This is why the European Union is so keen on having this kind of scheme as well as metered water charges. It wants paying for the system to be structured in such a way that people have a constant incentive to use the resource more carefully.