Maybe that isn't 100% luck, but one needs the luck above his skills to win big in gambling. Skills, strategies with good control and patience can bring small wins, but for big wins luck is always a must factor. Gamblers who are highly calculative and are into clear observation on the games will make good picks. Casino games need good bankroll to withstand while we're on a losing streak. 100% luck works well with lotteries.
When we are lucky enough we do excellently in casinos, you are right, the bad thing is when that luck runs out and that is when everything works out, referrals are something else, it is how a casino can reward a person that has many referrals, you must always have rules so that you can execute them, and they are always difficult to comply with, there are people who get involved and do tasks as well as airdrops and want to get the rewards for a while, but the rules may indicate that a referral or each referral has to deposit and play with a required amount and this is something that not everyone can meet.