From CME website:
".....generates revenue by selling advertisements on its network of television displays installed on inter-city buses and airport express originating in China's most prosperous regions, including the municipalities of Beijing, Shanghai, Tianjin and Chongqing and economically prosperous regions, namely Guangdong, Jiangsu, Jiangxi, Fujian, Sichuan, Hebei, Anhui, Hubei, Shandong, Shanxi, Inner Mongolia, Zhejiang, Hunan and Henan."