I think gambling site will be more profitable as there are many people who are looking to make quick money and now that has become much easier with the existence of bitcoins so gambling sites will definitely get higher traffic then dating sites in my opinion.
A question of course interesting about gaming sites or dating sites on the findings as there and there is different. If still gambling is carried out under certain rules, then on the dating sites there are only scammers. Take my answer as I'm not just an ordinary person.