Abstract: Systems, methods and computer readable media for computing message delivery reliability are disclosed. In some implementations, the method can include generating message delivery reliability information based on statistics of receiving one or more codes returned from one or more users. The method can also include routing a subsequent message based on the message delivery reliability information. The routing can include selecting an aggregator to deliver the subsequent message based on the message delivery reliability information. Generating message delivery reliability information can include receiving a contact identifier for a user device, and generating a code. The method can also include sending a message containing the code to the user device via an aggregator using the contact identifier. The method can further include receiving the code from the user device and generating statistics based on the sending and receiving of the code.

Abstract: Methods, systems, and apparatus, including computer program products, in which participation probabilities for content items in content item selection processes are adjusted based upon predicted performance measures. The predicted performance measures can be compared to one or more other predicted performance measures and/or threshold/scaling data to determine how to adjust the participation probability of the content item in the content item selection process.