I am not sure why everyone only speaks about bounty managers and not about other marketing person. There are a lots of forums and website which are good for marketing like insta, fb, youtube, tiktok which are good for marketing as well.. But no-one is mentioning that.
Most likely this happens because that is the more obvious option as we are in this forum and we know of the existence of signature campaigns, however you are right there are many ways to promote a casino and social media websites are key as casinos can reach millions of gamblers with a single post for free, which is something almost impossible to do with any other media.
Another good option is to try to hire celebrities for your casino, since people love celebrities, a casino that can hire someone that is easily recognizable will gain a lot of clients just because of that business relationship.
it's not about marketing those casinos on social media that is the problem but they need a corporate site like bitcointalk which has a daily inflow of members where they can get guaranteed that members of this forum will not only give a click, but they will as well give a try on the casinos, people tend to believe that whatsoever that comes from a reliable forum like this is legit enough and of a great standard to an extent because of the reputation here on the forum, that's why you see most of the advertising companies are secured enough to be trusted when advertised on the forum like this which has millions of users finding solutions here.