And house edge, together with the laws of probability are put in place so those who warn more from the casino in the long also only win a relatively small percentage of money, when compared to the complete value of their wager, which had been accumulated through their whole gambling history of the casino. I have the personal impression people under-estimate the importance for the business of gambling and they do not check on it when they first step into a casino, most gamblers believing it will be just matter of time for them to earn money out of it and walk away all happy, when reality is the opposite...
Even though, house edge does not have anything to do with banning gamblers from websites or gambling floors, I have read stories of people who cheat the casino in some way for them to have a bigger advantage which easily surpasses the house edge, basically slowly stealing money out the casino. One of the techniques more common being the use of asymmetrical card sets by the casino in games like blackjack.