Thought this was interesting from Macrumors (the bolded text is mine):
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Crucial - good place to buy RAM from all over over the world. They also have an excellent memory selector that allows you to choose memory based on your computer's model, rather than having to remember terms like PC133, PC3200, PC5300, 184-pin, 200-pin, DIMM, and SO-DIMM. Guarantees compatiblity and quality. Make sure to refresh the page a couple of times before you buy and clear your cookies as crucial uses different prices based on the operating system and browser being used (just to be sure, check the prices with different browsers like Safari, Camino, Firefox). Crucial's prices are variable - while they have a stellar quality reputation, you may consider looking elsewhere for a better deal.
Re: the first link - the pricing differences cited for merchandise online were days apart in most cases - and yes, prices on books etc. do go up occasionally. Or down. Something falls off the NYT bestseller list...price goes up. Etc. As for the travel sites - as one person noted, there are so many variables at work AND you will note that there was no discernible pattern with any browser or cookies on/cookies off, that it is pretty hard to jump to the conclusion that any sort of dynamic pricing is going on. Much more likely is constant price changes from the airlines, combined with server caching differences making for differences in the fares. I've conducted many an online search for air fares, using two different browsers at a time and every travel site and the airline sites themselves and haven't noticed any huge differences in prices. Slight - sure. From day to day - or sometimes even half a day - absolutely. (Booking a popular destination for the beginning of a school vacation is always a bit of a hair-raising experience! Does one book the first day the tickets are available - 330 days in advance - and risk paying more if lower fares appear later or does one risk waiting and either not getting tickets at all or paying even more? Right now, unless something pretty monumental happens to oil prices, I figure the sooner the better, but in the past it was a real crap shoot.)
Not sure about Robert Accettura's experiences: at first I thought maybe TurboTax cleaned up their act after he published that blog entry, since if you go to TurboTax.com now in all three of the browsers I tried, all of the prices were identical and offered the free option. Tried Safari, Firefox and Opera.
However, something was still going on last fall:
http://digg.com/apple/TurboTax_Online_Char...fari_Users_More - and the explanation may be in this forum response:
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I used to work for Turbo's competition. I'm sure they're doing something similar to what we did.
They're trying to figure out what price points will get the highest conversion ratio. Nothing more. We called it A/B testing. You have a control and then a number of variations of the control. Each version gets a percentage of the traffic. Numbers are crunched and the "winner" is chosen.
Has nothing to do with browser/OS and everything to do with them trying to make the most money.
Perhaps they've now chosen the "winner" (Gee...ya think FREE was the one that got the most votes??)
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I've also noticed a variation of this in some ads sent to my email from some online companies.
Yeah! And besides that, not many of those 'drugs' work as advertised, at least I've not seen any growth in areas they were supposed to 'enhance'! It's getting' to the point that you can't trust e-mail at all! 
As for as airline fairs, I'd stop worrying about missing a cheaper fair, ever.
As for as airline fairs, I'd stop worrying about missing a cheaper fair, ever.
Are these airline fairs anything like renaissance fairs?
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Are these airline fairs anything like renaissance fairs?
Yes but with more 'attitude indicators' or is that altitude...
I'm still looking for a gude gramer chequer!