US Patent 8473339 Automatically switching between pricing models for services

Methods, systems, and apparatus, including computer program products, that can include receiving from an advertiser a request for billing based on a first measure of services, determining from quality data related to the advertiser whether the first measure of services can be converted with sufficient confidence to a second measure of services, providing services according to the first measure of services, monitoring stability data indicative of the stability of the relationship between the first measure of services and the second measure of services, and automatically switching from one to another mode of determining a price to be charged the customer for services provided.