Incentivizing users to post in their topic (Against the forum rules)
Any kind of incentive to post in your thread is against the rules. But sportsbet gang have found an easy way to bypass this rule.
I'm not sure what you consider illegal here.
Yes, it is clear that Sportsbet dominates here and the fact that several high-ranking members are included only means that they have invested wisely. for example, I did not receive any offer to wear their signature or anything similar, but why would I when I am not particularly active or recognizable in the gambling part of the forum.
It is interesting that as a feature you mention how merit is distributed in Sportsbet threads, but you don't mention that Games & Rounds is full of Sportsbet's giveaways and raffles, and how much they have invested in building a brand on this forum. You don't think that this is one of the reasons for their dominance in gambling here?
From this group, only LFC_Bitcoin is a merit source (there is not much to complain about his contribution on this forum), everyone else is free to give earned smerit as they think is best.
I don't know if you are originally Sportsbet's competition, but nothing prevents you or any casino from applying the same strategy. Hire a few reputable members to take care of your (or any other casino) brand.
Unless there are no serious scam accusations against Sportsbet, there is not much room for complaint here.