This article paints a pretty good description of how price discrimination is used in online shopping and how places like Amazon try to extract consumer surplus. I don't know if I agree with the title's claim, though. If a product is shown at a higher place and you click buy, you're still choosing to buy the product at an accepted price, i.e. the value of the product is still worth more than what you're willing to spend, otherwise you wouldn't have bought it at all. How does that make you a sucker? Because someone else might be getting it for cheaper? That might seem unfair at first, but ultimately it's irrelevant. Other people have different opportunities for a lot of things. Complaining about what price someone is voluntarily willing to pay for a good is probably near the bottom of my list of injustices.