Baidu is the dominant search engine in China and the fourth most visited web site in the world. Being in China, of course, means that Baidu censors search results quite heavily (you won't find anything about a guy standing in front of a tank when you search on "Tiananmen Square", for instance). Baidu has made an arrangement for Microsoft's Bing search engine to return English language results for Baidu customers. Going along with this, of course, means Microsoft agreeing to China's censorship laws, a condition that Google has been very reluctant to meet, thus Bing.
“I think the best compliment I can give is not to say how much your programs have taught me (a ton), but how much Marketplace has motivated me to go out and teach myself.” – Michael in Arlington, VABEFORE YOU GO