stomachgrowls: I don't think they are scam they are legitimate casino but maybe they may just doing this for the sake of publicity or advertisement.
To OP are you part of the Earnbet team? I think instead of creating newbies accounts and opening topics promoting it I think you should create a good advertisement in a right way probably competitions, promotions or maybe signature campaign this kind of promoting attempt and using multiple newbie links wouldn't get you good publicity but maybe the opposite.
Not the kind of advertisement that the majority of us like for a gambling site, of course, we want to see an official announcement thread but posting this without a referral link is natural and not really surprising I have a lot of threads like this in other forums for projects I'm promoting,
it could be a task that he gets paid for posting.
Traffic is good for this gambling site but like all the other comments he should follow the right direction to promote the gambling site in this forum and that is creating a formal and official announcement thread and launch a signature campaign if he has a budget.