system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How do porn companies make money?

With such a large amount of free porn out there, how do companies make enough to survive? I assume ad revenue but is that alone their only source of income? Do they still receive ad revenue even with pop up and ad blockers? What is the average salary of a porn star? How much do they get paid for a single shoot?
gpt
One way is advertising, as mentioned here a few times. Banner ads alone can pay up to $1.50-$2.00 cpm (per 1000 impressions). Video ads are much more, I've seen them as high as $10-$15 cpm, but $5-7 CPM is closer to average. Serving millions of ad impressions a day will add up significantly. 

Also, despite the fact that there are shit tons of free porn available, a lot of people get subscriptions. Subscriptions are not that expensive but they do add up for a company. These days you'll get 4k quality videos, thousands of photos from every shoot, behind the scenes shit if you're interested, every video from every star on their roster. You basically get it all. Just like with drugs, there are casual users and there are hardcore users. Millions of them. Hell, with porn, it's probably not too far fetched to say there are a billion people using it in some way, shape, or form. 

A smaller, but probably not uncommon method in some respects, is money earned from stars' appearances at clubs and other similar venues. For instance, if a star is contracted to a major company like Brazzers and a nightclub wants that star to appear at their club for a night as a crowd draw, they might pay $20,000 for that appearance. The star would get a large cut of that, their management a small amount, and the parent company another small part. This is just an example to get the idea.