D&D.Sci forces the reader to think harder than anything else on this website
D&D.Sci smoothly entices me towards thinking hard. There's lots of thinking hard that can be done when reading a good essay, but the default is always to read on (cf Feynman on reading papers) and often I just do that while skipping the thinking hard.
Also related: Yudkowsky on making Solvable Mysteries:
If you have not called upon your readers explicitly to halt and pay attention, they are already reading the next sentence. Even if you do explicitly ask them to pay attention, they are already reading the next sentence. If you have your character think, “Hm… there’s something funny about that story, I should stop and think about that?” guess what your reader does next? That’s right, your reader goes on to read the next sentence immediately, to see what the character thinks about it.
Note for readers: "the list is symmetrical" = "the harder a medium is to make, the easier it is to consume and vice-versa."
Note for readers: "or better yet, at-least-kind-of-invents and at-least-kind-of-popularizes a medium like that" is the +0.5 in my (abstractapplic's) 2.5 intended answers.
Note for readers: dogfooding = using your own product