I also believe in this one, just think of this idea. Why do casinos offers much like a comfortable and even grand place and freebies like water, juice, alcohol, etc. to its players even though they are winning a lot? It is because even though players won the jockpot many times, the house earned it also as many times as the winner in a row. Where do they get those high jockpots though? Maybe if someone wins, they get doubled.
Not every casino has similar returns. Bet365 is big. like REALLY BIGG!. I know about many casinos and online sportsbooks that are barely managing. Heck even, directbet couldn't keep up with the high bitcoin fees and was probably why they closed 2 years back. They have an edge, but players these days have many options. In order to make money they need volume which not all casinos have these days.
This is true, in theory, the casino profit is 1% of the bets, better known as house edge, if she gets 1 million daily that means the casino is getting more than $100M in bets each day, that's crazy I know, but bet365 is an enormous platform, so, it's possible for them to handle that volume.