No doubt many successful casinos in Bitcointalk because they can running the campaign very well. I agree that casinos need to find which promotion that will runs good for them. But signature campaign is the most campaign that many casinos use to attract people attention.
A well run campaign can generate good results for the platform because as long as the campaign runs smoothly, many members of the forum will be interested and they end up doing their part really effectively.
We can see the results of that on this casino, I have come across a lot of the ads here in the forum, and first time I visited the rainbet casino was through the signature of their participants and I can say that their .site load pretty well and smooth, I have no doubt in the casino capacity to handle their growing community.
I have played at Rainbet casino several times. It is true that there are no obstacles and everything goes smoothly, they provide fast deposit options, as usual when a casino provides low fee coins such as TRX, SOL and BNB gamblers will definitely try to play there. All that thanks to Rainbet appearing in the signature campaign, because personally I make a benchmark for every casino that promotes it must be interesting to try.
Based on experience, Rainbet advantage is in sports betting where you can bet with combo options in one view.