Shouldn't this depend on the agreement? I mean in most cases brokers are the ones that are paying. Let me explain to you how the casino that I worked with was establishing their wins and losses. They had few different games, all from different game providers, which mean they had like 6 if I remember right game providers that gave them about 300 games.

These games were automatically tied like an affiliate, which meant that if you gambled where I worked at that time, the money you lost went to the game provider, and then due to that affiliate income, the casino made some of it back, usually about 3% to 10% depending on the game, and when you lost they lost nothing. So at the end of every month, the casino got paid from the game provider.