Always Clear your browser’s cookies before booking flights online or simple use your browser’s incognito mode. Many airlines and travel web sites (such as Expedia, Kayak, etc.) track how many times you’ve visited their websites. In so doing, they provide different offers and deals depending on the user.
To make sure you’re getting the best prices when you book air travel online, be sure to clear your web browser’s cookies and cache. This will make it appear as if it’s your first time visiting these sites, and you’re likely to see much better prices for your next flight!
Also, they realize Mac users are suckers, so they steer them to higher priced options
Orbitz has found that Apple users spend as much as 30% more a night on hotels, so the online travel site is starting to show them different, and sometimes costlier, options than Windows visitors see.