These are what we call the 'YMMV items.' Things that some people find in this work. We call them 'your mileage might vary' because not everyone sees these things in the same way. This starts discussions in the trope lists, a thing we don't want. Please use the discussion page if you'd like to discuss any of these items.
Foe Yay: The closest thing Acheron Hades has to a friend is one of his cohorts, who he likes so much that he took off his face when the original died and goes around grafting it to people. The relevant portion to this trope is that he mentions he wanted to put the face on Thursday next. No pun intended.
"Funny Aneurysm" Moment: The absurdly-exaggeratedly-bad-taste-modern-reality-gameshow Celebrity Kidney Swap turned out to have a real life counterpart only months after the book in question was published. Granted it eventually turned out to be a hoax, but still.
Genius Bonus: Some of the literary allusions can be quite obscure.
Hilarious in Hindsight: The Well of Lost Plots is where all unpublished works reside. Most of them, Thursday notes, are complete dreck. The Bellman in Well notes that "in eight months, we may completely run out of original ideas." ... Keep in mind, when this book came out Twilight still dwelt in the Well of Lost Plots.