There is no doubt that the most popular and probably the most effective way to promote a casino on Bitcointalk is to launch a signature campaign. But there were casinos that created their own tokens thanks to which the hodlers had a share of the profits. Thanks to your own tokens, you can also launch a bounty campaign and promote the casino in social media, youtube, blogs, tiktok, instagram etc.
Launching signature campaign with the BTC payment will be the most favorite things here, many people will be interested to see again at least what kind of casino it is.
However, to launch this signature campaign, a casino owner must have money at first because we all know how much it commonly costs. If the new casino has not have enough funds and has no their own native token, the signature campaign may not work at all.
But at least, a casino owner can create a good, informative, and also interesting announcement thread in this forum so that members here know that there is a new casino. Although this may not be interesting enough to attract more people to come. And, make sure that the team is active in the thread to answer every reply of the members, this will add positive vibes.
And actually many enw casinos are promoting thier casinos by advertising in certain games adv, this cna be also a good way. But once more, advertisement means you need to spend money to promote.