Microsoft has purchased Seattle-based travel search engine Farecast, known for its alogrithm that predicts the best time to purchase airline tickets, for $115 million. Tom Romary, chief executive of Yapta, told the Seattle Post-Intelligencer he heard Microsoft outbid Google and Expedia for the privilege. Before its acquisition, Farecast raised three rounds of venture capital totaling $21 million from investors. One of them, Madrona Venture Group's Matt McIlwain, said the deal returned more then five times they firm's early investment. "If deals like Amazon are home runs, this is more in the double or triple range," McIlwain told the paper. The Motley Fool wonders if Microsoft will use Farecast's algorithm to decide when to raise its bid for Yahoo.