I was, while typing my last post in this thread, watching the movie "Casino". It was the scene where a Japanese businessman wins two million dollars of the Tangiers' money, and is in the process of returning to Japan. So Ace Rothstein, the character who runs the Tangiers for the mafia, instructs his security chief to tell the businessman that the private jet, provided free by the Tangiers, has a mechanical fault, so that the man's departure will be delayed. The man, while waiting, is eventually lured back onto the casino floor, where he not only loses back his two million dollar profit, he loses an additional million dollars of his own money. Ace Rothstein's narration explains:
In a casino, the cardinal rule is to keep them playing and keep them coming back. The longer they play, the more they lose. In the end, we get it all.