ITA's Matrix is my go-to choice. I wonder if they sell search metrics to the airlines.
It is common knowledge among frequent flyers that you can get better prices sometimes if you're not signed in. For example, if you fly 100,000 miles a year with an airlines, they're pretty confident you're going to fly with them, so why not show you a slightly higher fare? The worst part: it works. I go to HipMunk sometimes and see a fare for $500 dollars less (on the same airline), but I still book through my preferred airlines, because the benefits are worth it for me: no hassle security, no hassle baggage (first on, first off), no hassle boarding, good chance of 1st class upgrade, etc.
The good news is that if you do find a lower fare on ITA (and pretty much only ITA), you can usually call the airlines and get that fare. Fares are bucketed into fixed "fare classes" so if there is availability in a cheap bucket, the airline MUST sell it to you.
The bad news for frequent flyers is that many benefits do not extend to these cheaper fare buckets. For example, if I want even a chance to be upgraded to business class for free on a transatlantic flight, I have to purchase one of the most expensive economy fare classes. Concrete example: I am flying to Israel in a couple months; for the cheap economy fare it was $1400, but for a chance at an upgrade it was $2,100. I took the $2,100 fare, because being in business to TLV is quite important to me.
Its unfortunate, but its how it is.
I'm not necessarily doubting that this is a thing, I've just never seen hard evidence.
>If you visit the airline's site multiple times, you are not penalized (price-wise) for that.
>However, given well-known yield management techniques, you are likely to see the price rise over time.
>Variations such as the modulation on the time of day make generalizable comparisons harder.
>If you browse the site in a fresh browser, you may see a different offer but the resulting price is substantially similar. This kind of makes sense as a marketing ploy — try harder to attract the comparison shopper, but sell them the same ticket in the end.
http://skeptics.stackexchange.com/questions/9597/do-ryanair-...
* http://travel.stackexchange.com/questions/16581/does-browsin...
* http://www.quora.com/Airfares/Does-searching-for-air-tickets...
* http://studenttravel.about.com/od/planes/a/The-Students-Guid...
Short answer: they use cookies to track your searching behavior, and raise fares if you keep looking with the intent of getting you to panic buy. Correlates of high income (e.g. using a Mac or an iPhone) also hurt you.