It's hours/money spent/$ per hour split on paid/free games / non-games according to the link.
Pretty useful, but obviously does not know about bundles etc.

While probably computationally too expensive, I would like some system where up/downvoting isn't about objective quality, but only about personal preference. Essentially the system would "cluster" up/downvote behavior from users like youtube clusters like/dislike of videos and then recommend posts which people who like the same content as you like and people who dislike content you like dislike. I am not sure how many clusters/dimensions you would need though and I guess individualized sorting would quickly become computationally prohibitive as you would have to do a scalar multiplication of the post-dimensions with the user-dimensions for each post and then sort the stuff.

I don't think so, because otherwise judges would never have difficulties judging some known behaviour.

I am not aware that holocaust denying websites are blocked via DNS or any other means in Germany.