I would avoid casino and adult, it's simply too competitive and volatile (IMO).
Consider non-elective medical procedures and those markets (dental implants, breast implants, cosmetic dentistry) - in two decades heavily in this space and the need for effective links exists as strongly as ever, plus it has celebrity tie-ins and constant news and new products. It's also a preposterously lucrative industry (a full upper/lower dental implant set = $70,000) and it's never going away. Good luck.