Events interpreted as aversive tend to elicit effects that influence our response. So if an average individual is in a casino gambling and he or she is on a losing streak the response is likely to be to stop gambling–withdrawal. Generally speaking the purpose of the response is so that the individual will have money left over to get home. This sort of response, however, is bad for business and casinos are doing something about it.
What can casinos do to keep me gambling my money, you ask? A Radiolab reporter found that, for starters, casino workers can be very nice to you in effect giving you a positive experience. The next thing casinos can do is reward you with, not money (they keep that), but with random gifts such as gift cards etc. These gifts are not of major significance by any means but make a whole lot of difference in the long run. So much so, that the casinos are making the practice standard protocol for the purpose of keeping their customers returning to the gambling table.
How the effect works: van Steenbergen et al., (2009) found that randomly rewarding participants in a conflict adaptation task did not affect their performance, a negative effect was found for those that did not get rewarded or even lost. The reward in this context is perceived as attenuating the negative effect or experience of the event. The idea is that the effect of losing while gambling can be counteracted by rewarding customers with other smaller gifts leading to a more pleasing experience.