The document provides a comprehensive overview of the digital out-of-home (DOOH) media industry as of May 2011, including its definition, fragmentation, and projected trends. It highlights the growth of DOOH, particularly in key markets like the U.S. and China, while detailing various types of digital networks and their revenue potential. Key players and case studies illustrate industry performance and innovations, along with insights into future challenges and opportunities in the evolving landscape of digital advertising.