[citation required] but even if true, getting site owners to opt-in to exchanging their user's privacy for psychographic and demographic correlations seems mate

[citation required] but even if true, getting site owners to opt-in to exchanging their user's privacy for psychographic and demographic correlations seems materially different than Facebook's "no opt out" on a relatively unrelated feature like a Like button on a 3rd party site. They used to and could again make the button work without using it to gather browsing data.