How do sites like Pornhub rank for random porn search queries?
 

If you type in just about any porn query into Google, sites like Pornhub will invariably show up on the first and second page. But often times the page doesn't usually 'exist' to have been previously indexed by Google, instead it's a php string with the search query, showing the results as though Google had typed in the search term itself.

I've been researching academic studies looking at the effects of VR porn on users, and so I typed into Google - "vr porn study", and even here Pornhub is on the first page :

https://www.pornhub.com/video/search...+reality+study

Is it something these sites are doing actively to show up in the results for every adult search term, or is it just the fact that they have such huge page authority/backlinks, that Google automatically assumes they will 'have the answer' to your search query?

Goggle is SOOOOO useless these days.

There are many reasons for that: location, search history, etc. If you go to settings and choose USA and English language, Pornhub should appear on the 3rd page of SERP. So it means you visit pornhub a lot hehe

Under the table payments and feelups.

I would guess they auto generate search pages based on related queries from an api like ahrefs.

This is the answer because pornhub isn't the only site to have search result pages show up for terms.