Another platform where online casinos are most welcome is the adult platform. A friend told me that he keeps seeing three top online casinos, 1win included; the other two are BCGame and Stake, Online casinos have a market in this industry, and not all online casinos are extending their presence here. This is an untapped marketing platform.
I don't think adult websites are untapped tbh. If what you said is true, doesn't that mean casinos already compete on bidding those ad slots? I'd be surprised if the owners of those websites choose casinos simply because they like or use them. Judging from the traffic it's very likely that the winners are those who pay more or offer more benefits for the owners.
I believe there was a discussion about this on this forum. Can't remember which thread though.