One thing with campaign (and by campaign, I assume forum signature) is that its best when it's done long term, yes, it cost money and all that, but then, it wins more customers for the casino if it's the campaign is allowed to run for the long term, check out all the casinos that have their campaign running since God knows when, they are all doing fine..
But then again, I still agree with your that every casino have their marketing term and it's up to them to research and know what marketing strategies fits their business, maybe based on marketing budget/allocation available to the marketing team.
Of course, signature campaigns are effective in the long run, while short campaigns lasting just a couple of weeks have almost no effect. In the case of Betfury, we see that its marketing team is not particularly fond of long signature campaigns on this forum and prefers to promote its platform through social networks. However, they don't refuse to promote Betfury on this forum completely, but even if they decide to launch new signature campaigns, they only do it during some big events, as it was a couple of times last year.