1) niche and microniche stuff will continue to convert well on pay sites because there is limited content.
2) if your still pushing hardcore or anal sex sites then your an idiot and no shit your not getting sales
3) everything changes over time. TV shows are now available on programs like Hulu or Netflix, as well they are still free on ABC.com. If you want to compete in that space, then you have to have the money to. The small guy is getting pushed out with competition that has deeper pockets.
Believe it or not, the same thing happens in the mainstream affiliate network too. Years ago, a half wit ape could of made an easy $1k/mo with very little effort with some dumpy single page "review" website and some AdWords traffic. Now, all the big players are pushing their sites and driving profits down to where it is being impossible to compete.
Here is my
on this... if you want to stay alive in this field, then either have some money to spend or get creative in what you do