Go talk to Adultking, he says the adult industry is doing better than ever.
The problem is Tubes have nearly all the traffic and they don't spend money to join paysites.
If you don't want to shoot content or deal with models, then you're going to have to buy it in and at todays margins forget about it.
Try opening a Tube site and pushing penis pills and dating sites which have no girls.
In fact a free dating site might be the way to go and start as an affiliate and built towards selling ad space.
Otherwise concentrate on another trade.