I live in New Orleans, which has an unusual concentration of strip clubs. I've heard people who work in them complain that to use a credit card, they require you to let them photograph your ID, make an impression or photo of your card, and have you sign a carbon copied form.
This gives some customers cold enough feet that they head out, but the reason is that people will run up a serious tab with lap dances, champagne and whatever else and then strenuously deny they ever set foot in such an establishment. I'm sure porn has the same problem.
It's pretty gross as far as I'm concerned. There's no legitimate moral distinction between falsely saying you never signed up for (random porn service) and Netflix, or saying you never got a lap dance and saying you never went to the ballet, and people acting differently causes legal businesses with avid customers real harm.
"Paying for porn is stupid. But I just have to have everything of this specific person or fetish, so I'll pay, scrape, then chargeback."
I'm skeptical that it's a lot of kids because I feel like finding free porn is pretty darn easy if you try. Why would they ever bother with all the friction that goes with charging their parents CC?
(Just checked, the top three Googles for "free porn" are sites with a lifetime of free porn)
Porn is much more about revealed preferences in isolation.
Just a FYI.
They own Brazzers, Digital Playground, Reality Kings, Twistys, Babes, Sean Cody and Men.com for production studios.
There are thousands of tube sites, two of which have more traffic than those mentioned above. There are hundreds of porn studios, many which are more popular than those listed above.
I download a lot of that content too (sans the chargeback). I like to have it available locally, even when the internet is down, when the site decides to take a particular video down for whatever reason, or even when my account expires. And paying for it makes it just a little more likely they will continue to produce more of it in the future.
I never worked in porn but I did work with payment and clearance systems from carrier companies a long time ago, think billing customers for SMS messages to specific numbers and then getting clearance for the carrier for the money. The risk of fraud or any kind of weird issue is stupidly higher for porn. Either simple "customer doesn't have the money" fraud or "the police knocks on your door because you got money from X customer" fraud. So maybe you need more people or better systems to deal with it while still being profitable. CCBill charges are huge when compared to other credit card processors.
It's easy to reduce costs and complexity until the easiest solution to keep or improve current margins is don't do porn.