Free money definitely attracts users but it is not always available it is only given by some site to shill their site but no site gives free drops, spins or other bonuses for long time. So the users are more attracted to the sites which provide bonus facility for a longer period of time. But casino sites offer more bonus facilities to those users who deposit high amounts and gamble regularly. that is the great strategy of there to bring gamblers on there site
Airdrop like cant be considered as free money at all because its too small to withdraw and you will need to gamble or deposit your own money just to withdraw the money you collected. Its just a waste of time to hunt this kind of air drop due to its value and timer compared if you just do a job or hunt a side hustle that pays better rate.
Faucet is meant only to try the casino feature and not as a source of profit. User that staying on the casino for this kind of mere bonuses usually doesnt play at all just and just leeching the casino.