Biggest issue with this is the modern web ads don't even work.

You get ads for fridge AFTER you bought one since they now know you browsed them.

What works is content based advertising - so advertise a power drill on a woodworking hobbyist site. No tracking required there. Conversion can be obtained when user clicks a link via redirect. Like in the good ol times.

But this modern approach that massively invades privacy has been sold to businesses and now they require it even though it is probably ineffectual.