A computer implemented method is provided for monitoring the quality of service of a service provider, the method comprising the steps of receiving first and second reports from first and second clients, respectively, the first and second reports having information relating to the quality of service provided by the service provider to the first and second clients, respectfully, and estimating the quality of service of the service provider by aggregating the information in the first and second reports and comparing the aggregated information with conditions set forth in an agreement involving the service provider.