do you think you can earn really big money on gambling? people write different things everywhere, so I'm curious to find out here
With the referral program, yes someone can earn big money if he/she can get whales as his/her referral.
I'm pretty sure there some people who earn decent amount of money from referral system, but it is rare to find them share how much they have earned.
There was also other way to earn, where people can invest in casino's bankroll and I've seen some people earn nice profit by investing.
When it comes to gambling yourself, the chance to earn/win big money does exist as long as you are lucky and you can stop at the right time.
If he is a gambler and his goals is to make a lot of money then that is unlikely but if he is only referring users, he can make money and the earnings can depend on the casino and to the gambler that he refers because not all casinos are the same rates but some offers small percent only while there are some which offers huge percent.
As for the gambler, not all gambles or wager more but some are the complete opposite. That is the one that we must look for if our goal is to earn a decent income via referral rewards. This is a passive way to earn but another way to earn passively is like you said bankroll investing tho it only requires a starting capital.