On Jan. 31, Steve Ballmer, CEO of the software giant Microsoft, sent a letter to the board of directors of Yahoo, offering to buy the Web company for $31 a share — a 62% premium to what the stock was trading for at the time. Yahoo rebuffed the offer, saying it vastly understated what the company was worth. Since then, Yahoo has watched its shares become worth 60% less, as investors grow ever-more-disenchanted with how the firm stacks up to Google in the game of squeezing ad revenue from the Internet. In November, Yahoo CEO Jerry Yang stepped down and the company made overtures that it might be open to a Microsoft deal. Ballmer has said in no uncertain terms that he's no longer interested in buying Yahoo.