A little more...
"Retailers are increasingly charging “personalized” or “dynamic” prices based on your online footprint. They manipulate prices, trying to charge you the max they think you’re willing to pay. You could be sitting right next to someone, looking at the same online product, and be charged more just because of a website you visited.
You're probably familiar with how common this practice is in the airline industry. That's all thanks to Google's ITA QPX Software; which provides solutions to airlines to price "by market segment, point-of-sale, channel and even user."
That profit comes right out of your pocket because they decided you were willing to pay more for your flight based on tracking.
The worst part is, this sneaky pricing tactic has long been used in other industries. The Wall Street Journal ran a study on the matter as far back as 2012: