Each platform has its own marketing or promotional plan. In this case, there are many casinos that reduce promotional activities on the bitcointalk forum and increase them elsewhere. Moreover, many casinos have budget issues.
I myself have managed the signature campaign of a Telegram-based casino. What I have observed while managing this is that most of them expect that, since they are investing a large amount here, they will probably get huge traffic from here. And many do not even understand that signature campaigns are not just for gaining traffic, but for building a long-term brand. And this is why many of them don't keep signature campaigns running on this forum for a long time, they focus more on other promotional activities.
Yes, Those who do this want to promote their projects quickly by marketing them, but the marketing systems are different in this forum, so they cannot stay here for a long time. Other projects running on the forum for a long time are extensive projects with no problem marketing to several sectors. Due to this, they continue to promote this forum for a long time, which increases the visibility of their project.
What actually good is they choose the right platform to market their casino since from here there's really a good chance that they could attract lots of gamblers especially that Poker is one of games played by lots of people here.
Its just they need to make their casino became more visible so that they can attract lots of gamblers to play on their site. For now they need to have more exposure since we cannot deny the fact that lots of casino offering same games and they need to became more attractive so people would shift and love to stay here. But everything is good since so far they do all necessary things to market well their casino.