I'm not that familiar with all the recent bonuses etc, but this can't be right. That would mean that if a player referred himself, which is not allowed but could happen, he would be making 0.40% of the amount wager in pure profit (with 0% house edge). If that were the case, the site would probably have gone bankrupt already.
And even if a player didn't refer himself, but was legitimately referred by another user, the site would still be making a loss on such a player (unless he was unlucky in betting).