This kind of scheme does exist in cryptocurrency trading, a lot of platforms are driven by affiliates and commission is normal.
The paid signal group also exists where you can invite someone and get a commission but the commission I think is only 1 time for this.
I guess I was talking about commissions from trade fee/commission. So it is less about getting someone to sign up but more about getting people to trade. Hence they do not care if you deposit $1 each time. They want you to get hooked and trade and trade, More volume is more commissions. They make money if you lose and if you win.
The number of people you refer won't matter at all, say you only referred 1 or 2 people but as long as they are a whale trader because you can still be able to earn massive profits each time they make a trade but if not, then you might need to gather more people to sign up under you. Not all people are a fan of these commission thing because they think inviting someone else is hard as they already had a bad experience before.
You are already lucky if there are people who will sign up under you but the tricky part is to make these people stay. Maybe you will have a better success rate if you have a skill in marketing and you know how to sales talk, add in if the platform is naturally good.