Why buy if free?
This has always been a problem selling porn. In the beginning it was why buy magazines if TGPs give away free images?
Then it was the DVD industry that suffered. Why spend $30 for 5 scenes when for $30 you could get a months supply of scenes?
Now it's why spend $30 a month when Tubes give you 100s of new scenes a month, plus all the existing scenes for free. No trapped into spending money on a good tour and crap members area, no emails month after month, no cross sales, no risk of getting your card banged, the wife finding out, etc.
The reasons to buy have to really good after all the negatives of paying for porn.
Added to this problem is the moving market syndrome, marketing people will be familiar with that term. Where are the new customers going to come from to replace the ones that left?
For years the Internet lived off the millions who bought offline porn, when they all came online where were the new customers coming from? India, China, Africa, Asia, S. America? No the amount of traffic that bought porn wasn't worth a damn. 18 year olds maybe could replace those leaving, no they were happy to get wanking material for free and tubes happy to supply it.
New markets such as Cams, solo girls, micro niches, etc. This is the silliest of assumptions put out by affiliates and traffic generators who know nothing about marketing or selling. Because it assumes all those who now buy Cams, solo girls, micro niches, etc never bought porn before.
No they all bought porn before and all they do is buy the porn they like the best of what's on offer. They don't buy no porn at all because it's not live, a girl shooting herself, the micro niche they're into. These are marketing tools used to take customers from someone else to a new site.
There's still money to be made in porn, but not what there would be if affiliates had not been paid 50% and given everything to aid them throw away free porn.