This document discusses revenue generating value-added services (VAS) solutions for mobile operators, focusing on mobile advertisement and sponsored calls. It notes that competition among operators is causing pricing challenges and existing VAS services are saturated. Sponsored calls are presented as another form of mobile advertisement that allows advertisers to sponsor subscribers' phone calls in exchange for listening to advertisements. The document outlines different methods for implementing sponsored calls and compares the methods. It also describes the key players and roles in the sponsored calls ecosystem, including advertisers, agencies, aggregators, and mobile operators.