Efficient Frontier analyze Search Engine Marketing (SEM) data across multiple vertical and regions, their latest quarterly Search Engine Performance reports, revealed that “three of every four paid search clicks happens, and 75% of every paid search dollar is spent on Google.” The stats cover Q4 of 2009, and show Google’s share of paid search clicks rising from 71% in Q3 to 74.4% in Q4. Yahoo’s share of paid clicks, meanwhile, dropped from 24.4% in Q3 to 21% in Q4. Bing’s share was down slightly, but remains up 31% year over year. Google is the clear leader, but the company’s 74.5% share is actually down year-over-year. For the year, Yahoo remained steady at 20.4% of spend, while Bing grew 25% from Q4 2008 to Q4 2009,” Efficient.