"If Google.cn is shut down, the only real alternative is to go to Baidu," she said. "If Baidu were able to get the majority of Google's market share, that means we are looking at a player with 80 to 90 percent market share in China." Little known abroad, Beijing-based Baidu is one of the world's most-popular Web sites based solely on its following in China, the world's most populous Internet market with 338 million people online as of June. Web traffic monitoring company Alexa ranks Baidu as the world's 8th most-visited site.