I think the issue of whether it is morally ok or not is a sticky one as I guess many would say our business of promoting online casinos is immoral, so I am not going to go into the moral side of things, but my thoughts are that if someone visits a porn site – they are there for one reason – To look at porn – I doubt they would head off to a casino when they had porn on their mind in the first place.
So my personal opinion would be that it would be a waste of time promoting casinos on porn sites.
Just like any industry really – Example – you wouldn’t promote porn on a casino as one would assume that if someone goes to a casino its because they want to play casino games – not watch porn and you wouldn’t promote a pet shop on a site all about cooking recipes.
I guess it really boils down to the old adage about targeted traffic. If its not targeted, the click throughs are very low.