Did you ever think about the design of a newspaper? The artifact has some unique features that have made it so attractive to read in.
There are a lot of factors that go into the subliminal affordances, affordances that one may want to look at. Designers have to first think about the way an article gets read. You can control that. But then you go up a level. A newspaper has multiple stories. How do you decide what story should be adjacent to what story? So how do you kind of orchestrate serendipity?
What topics go together, what topics have some sort of connection. Where would you like to introduce the reader to something new or different?
You also have tangible limitations. Above the fold for example. How can you orchestrate what people see, not see, or get a glimpse of? Designers of a well designed front page understand stuff happening above the fold versus below the fold. Things that are adjacent that would capture your eye that you wouldn’t necessarily think you wanted to know about, but capturing enough of it to say, “Oh.” So it would actually orchestrate serendipity for you.
But to orchestrate serendipity, you have to be a damn good designer.
On the web, most of these design decisions have been taken over by algorithms. People try to use social signals of, “My friends reading this article” and so on.
Those are complimenting the sources that designers used to use. There are good algorithms that do smart page layout of newspapers today and you use all the additional information you’re talking about as well to do that. I still believe that the human eye should have a say into how things look like. You just can't fully fall back on computers making the choice for everything.