It’s all about when to buy contends Farecast.com

"Farecast.com, a startup in Seattle, which has attracted $8.5 million in venture capital, has a business strategy that promises to help leisure travellers find out when to book airfares to get the lowest prices. This strategy is based on the belief that what counts is WHEN to buy, as opposed to whether or not to buy."

[EyeforTravel]