Basically, does anyone know how it all works ?
I can only share my experience from my agent and that company more or less insta-exchanges my crypto deposits into fiat. Plus they charge some more fees and have low exchange rates. And imo this is the only way to ensure you remain solvent, when you accept crypto payments, but the gambling/betting accounts is run in fiat currency. These gambling sites (and agents) don't need to gamble, they make money anyway.
As for the bonuses, this is a safe business, otherwise such generous "gifts" wouldn't be given. In games of chance, nearly all customers will lose their deposit+bonus before they are finished with their rollover requirements. Every now and then a customer might get lucky to get to the point to withdraw some winnings, but this is easily covered by the losses from all those other customers. In skill-based games, that ratio is a bit more disadvantageous for the operator and thus the bonuses are smaller - you maybe get 100% bonus with an amount X as max requiring 5-10x rollover and minimum odds of around 2. You will have more customers, that will be able to withdraw, but it's still profitable. In an ideal scenario, you already make money with giving out bonuses and you will maybe be able to keep 30% of customers longterm and these will lose more at your site then.
He is right about that. When a certain gambling site accepts crypto, the exchange rate of converting from fiat to crypto will have lower exchange rate as compared to existing market rate.
That alone, they can already get substantial amount from the player even if they are saying they are charging minimal fees.
Also, most casino sites have good amount of bankroll even at the start.
The reason why there are some players will ask about the bankroll status to ensure they can pay in case someone wins.
But in any case, some casino sites will attract players to join in their bankroll investment.
This is one way also, to increase their money on their coffer.