Like you could just plug it into any playlist of songs, movies, or books, have it do some algorithmic analysis, and spit out what you would probably find fascinating.
The end result was underwhelming- it never really captured the characteristics that I actually liked about particular songs, and ended up being crappy or so narrowly tuned that it lacked enough variety to be interesting.
The concept is still around, but with less scientific sounding fluff and, I think, more relaxed parameters for recommendations.
It's truly a historic achievement and it's almost sad how the massive effort mainly resulted in a private database that's primarily used for a failed Spotify competitor
Apple Genius did something similar and it mostly worked not badly because it was drawing from songs in your collection already.
You're more likely to like songs in specific genres and time periods and songs that are popular generally. Once you get beyond that, it gets harder. And the situation is probably even harder with video unless you basically watch superhero films.
Which is basically what HN is.
The perfect Netflix customer is one always on the cusp of cancelling from lack of use but never actually does ...
It still chuckles me up when they send me an e-mail once in a while, about what I might like based my past viewing preferences.
Note: My GF, has a profile that she uses sometimes, but mine haven't been used since the account was created.
But, yes, in general friends with at least reasonably similar preferences to myself are almost certainly a better source of recommendations for video, music, and books than a recommendation engine.