There's a difference from a normal person perusing

There's a difference from a normal person perusing the show or a F&B guy or the people manning the booth across the way or a dude that sells prizes to casinos being interested in a game and a Slot Director being interested after hearing the game can be played to an advantage over the house.

Tell me what happens in a casino if you can play to an advantage over the house? Think blackjack. What happens to the player when they are good enough to have an advantage over the house once in a while?