Farecast, a Web site that uses science to find air deals, has launched new features that one analyst called "a very big leap for consumers" -- with a caveat.

Using the key feature, Fare Alerts, deal shoppers can get free daily e-mails that advise them to book now or postpone booking their airfare, based on whether prices on their selected route are predicted to rise or fall in the next week.

Users of Fare Alerts get a daily chart showing what the lowest fare on a route has recently been; how much fares are expected to rise or fall; and a tip saying "Buy" or "Wait," based on this data.

Get the full story at the Los Angeles Times

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