Do casinos pump extra oxygen into the air in order to make gamblers feel more energized? I've heard this rumor quite often. The Betfirms.com blog
uses some common sense to debunk it:
According to my Captain at the local Fire Department, “pumping oxygen into a casino would be a tremendous fire hazard that would greatly increase the flammability of all other objects. Any small fire, anywhere in the hotel, would be fanned and magnify itself by pumped oxygen.” As for the risk/reward opportunity, no casino would ever entertain the thought.
That makes sense. It wouldn't be good for a casino to encourage fires to spread, especially since people like to smoke a lot while gambling.
Betfirms.com traces the legend back to Mario Puzo's book, Fools Die, in which Puzo described a fictional Las Vegas Casino, Xanadu, that pumped in oxygen.
But casinos definitely do pump in smells, which they believe encourage people to gamble more. (They tend not to identify the smells, because they don't want to give away trade secrets.) In Elephants on Acid
I described a 1991 experiment conducted on the gaming floor of the Las Vegas Hilton, in which it was found that gamblers exposed to a pleasant odor spent 45% more money at the machines than those who were not exposed to the odor. A lot of retail stores have also bought into the "smell sells" theory. Though I think it's more marketing hype than reality.