Finding the best deal online can be a very time-consuming endeavour, and unfortunately, it's not one that can always wind up truly working in your favor. Many studies have been conducted in the past that have shown some major variances in online prices, based on a number of different factors. Even if you think you've found the best deal on something, a person standing right next to you could very well find one better.
To see the effects of these practices today, researchers at Northeastern University enlisted the help of 300 people who noted their experiences on different sites. As you might expect, some very interesting findings came out of this. Would you believe, for example, that not being signed into Orbitz or CheapTickets will result in a fee that's $12 more expensive? Or how about Travelocity charging iOS users $15 less? Here's a really odd one: Hotels.com and Expedia show prices 10% higher to people completely at random.
This practice might strike some as being illegal, especially since it's discriminatory, but it's kosher as far as the law is concerned. If this was considered illegal, then so too might coupons be, or buyer rewards and things like it. A common practice nowadays is to have flash sales, where a special price becomes available for just a short time - as long as a typical shopping visit.
That's all fine and good, but what's frustrating is being a consumer who's actually not getting the best deal. If there's an upside, you might not even realize you're not getting the best deal, but when you know that Travelocity gives iOS users a $15 discount, it wouldn't feel great when hitting that booking button on your Android device.
Sadly, as informative as this study is, there's really nothing in terms of a lesson that comes from it. You're simply not going to know if you're getting the best discount unless you know someone who got a better one. All you can do is shop around, use different devices, and hope that the best deal you're seeing is in fact the best deal, period.