You will receive a percentage of their commissions on the exchange. But if you invite friends to register for the exchange before December 20, 2019, then you will additionally charge the CNB coin. You can find out the exact amount on the Coinsbit website in the referral program section.
This is a very cool offer from this Coinsbit exchange. The only mandatory passage of KYC is a bit confusing, but you can get used to it already. Almost all exchanges introduced KYC.