Those are websites you have to pay, not websites that pay you to use them.

Yep, my bad I misread.

That existed in past. It was a program you had to run, and it would force you to watch ads (while browsing?). IIRC it embedded MSIE. I was still in high school, and my classmate who had cable internet would run this almost 24/7. It made him earn a couple of hundreds of dollars (end of 90s). There were also all kind of hacks to make it not so annoying (because you had to watch it all the time). Eventually, they quit paying.

There's also a TV you can get for free (it being worth 600 EUR?), but it has a camera and watches your living room 24/7 (if the TV is in your living room?). It also has very strict ToS.