Travel search engine Kayak has launched a new "Best Fare Trend" graph to help consumers keep track of the lowest fares found on their preferred route and travel dates within the past 90 days. The idea is to allow people the chance to see what a particular route has been selling for in the past in order to use that data to compare current prices. It's a good idea and a useful, if not perfect, tool.
For example, say I'd like to fly from Boston to San Francisco on August 24. I'd do a search for today's lowest fares on Kayak and see a $298 round-trip for the dates I'd like to fly. I can then compare that price with data over the past three months using the "Best Fare Trend" graph to see whether $298 is cheaper, more expensive, or about the same as the lowest fares on this route and date when others searched for it in previous months.
Again, useful but not perfect, because the graph is limited to searches performed by Kayak users, and further limited by the specificity of my search. If my route isn't a popular one (say, Des Moines to Moscow on December 31), there may not be sufficient data to put together a reasonable comparison. It should be noted, though, that Kayak says there are currently graphs for some 415,000 route-and-date combinations.
My overall take is that this is a somewhat helpful tool that still has some kinks to work out. In general, I like it, and I'm always in favor of more tools to help consumers get the best deals.
You can find the "Best Fare Trend" graph in the upper left corner of the flight results pages on Kayak.