One of the least appreciated, but smartest, moves Yahoo has made in the past year is to launch Yahoo BOSS , its open search APIs which lets developers create their own custom search engine using Yahoo's algorithms. We use it to power search across the TechCrunch network. And we are not alone. It has become immensely popular. By last May, Yahoo BOSS was serving up 30 million search queries a day . You can see the rapid growth in search volume in the chart above, which comes from a Technology Review profile of Vik Singh, the 24-year-old engineer who was one of the main champions behind Yahoo BOSS. (He is one of Technology Review's 2009 Innovators Under 35 ) At 30 million queries a day, that comes out to about 900 million queries a month, which would make Yahoo BOSS the fourth largest search engine in the U.S. with about a 6 percent share. That is just below the 9 percent share (and 1.2 billion queries a month) comScore estimates for Bing.