Earlier quoted context omitted.
Are you allowed to sell your kidney in the US? (No, you aren't.) This means that a site operator can't offer you access to a super awesome news site in exchange for your kidney. They can't get away by saying "but you can choose not to use the site". Well, Europe does the same thing for your personal data.
Trading a kidney for access to a news site would obviously be insane, and we should have laws to prevent insane people from harming themselves. On the other hand, if a person of sound mind decided they would rather have $1,000,000 than both of their kidneys, why shouldn't they be able to sell one, logically? The idea of selling one's organs sets off the human involuntary disgust/outrage reaction ("of COURSE it should…
Thought experiment: a multi-billionaire wants to beat a human to death, and offers $10 million for it. A grandfather decides he would like to take that offer, for his children and grandchildren. Would you allow that?
If you also would not allow it (that's what I hope), then where is the proper boundary? What should we outlaw, and what allow?