The one YOU can sell!
I do real well in my niches (amateur, teen, sisters and twins) but not everyone does. On the other hand, I can't sell tranny or MILF for shit. Maybe it's because I prefer women with real tits and no cocks.
A lot has to do with the fact that I know these niches and have been building traffic in them for years. I can also relate to the guys and girls that buy in these niche - I can't relate well to the guys that want to watch things like sleep assault, mature women, or gay - so I don't try to sell to them.
Just my
