[Schwolop]

Almost every type of "show me a filtered subset of something" website could benefit from your first feature - basically an "I've rejected this item for reasons your filters can't support, and never wish to see it again" button or checkbox.

Unfortunately, almost all such websites are supported by vendors paying to have their wares promoted to users, and letting users _not_ see them isn't what the vendors want. (e.g. in real estate searches, there are plenty of houses that meet all my criteria but which are terrible for other reasons and I'd prefer to never see in my results ever again.)