Read more about the gambling industry:
The New Yorker: Royal Flush
"The Wynn Casino Operations department monitors the returns of every gambling device in the casino, and the room's yields were falling short. After some investigation, it became clear that the problem was a demographic one. Men weren't playing these games; women were."
Biological Psychiatry Journal: Dopamine Receptor D4 Polymorphism Predicts the Effect of L-DOPA on Gambling Behavior
"There is ample evidence that a subgroup of Parkinson's disease patients who are treated with dopaminergic drugs develop certain behavioral addictions such as pathological gambling. The fact that only a subgroup of these patients develops pathological gambling suggests an interaction between dopaminergic drug treatment and individual susceptibility factors."