It's designed for the gamblers to gamble more in their website. I'm not a VIP myself, but just by looking at it, I guess it's pretty obvious that in order for your rank to increase, you need to gamble even more. It doesn't give you a real edge whatsoever, but it gives you some cashback or in this case, rakeback.

Well, while being a VIP gives you many benefits or perks like rakebacks, free spins, or some bonuses, these rewards are structured so that you as a gambler will play longer and spend more money, and based on statistics, the longer we play, the lower the chances of winning. Your odds of winning are still the same whether you're a VIP player or a regular player, and in my case, I don't aim for being a VIP at all because not spending too much money is one of my priorities always. There are a few here that are aiming for that VIP rank, and there's nothing wrong with it. It's just that majority can't afford to be one.