Farecast, Farecompare and a number of other travel sites made the idea of data crunching at the front end extremely popular with users.
Such scientific chores such as displaying when is typically the best time to buy a ticket on certain airlines became quite a usual and often core feature of websites as they tried to differentiate themselves from the metasearch engines already in the market.
Kayak has now done it the other way round, trying to get the search bit right first, with a slightly watered down version showing search volumes and average fares across its network of destinations.
Kayak Trends soft-launched a few weeks ago and comes under the auspices of the wonderfully titled "chief scientist" at the company, Giorgos Zacharia PhD.
The basic tool within the system is a constantly updated index of overall market demand for travel - today, for example, shows the index at around 15% lower than 12 months ago in terms average market value for flights and hotels around the world.
[While this may sound like positive news for travellers, data indicates that this has increased by 10% over the past three months]
Elsewhere, Kayak has re-created search volume data to indicate the most popular destinations on the Kayak site. There is also biggest upward and downward trend data.
Scientists and marketers at Kayak will be hoping that this kind of transparency of data is popular amongst users, not least because it shows off the myriad of destinations the company has in its search workbox.
But with 35 of the top 50 searched destinations located in the US, data like this continues to indicate the still very localised nature of its user base.