The answer is not, "Because they are American..." This is consistent with what we know about rewarding people in the workplace. If you offer someone a vacation or a bonus to their paycheck, they will more likely pick the vacation. It's not something they would regularly pay for on their own and "feels" more like a reward than a bonus, which would likely go toward something mundane like a paying credit card debt or getting ahead on a car/mortgage payment. Offering the choice, though makes the vacation less appealing because of guilt. This gets into the psychology of choice. Interestingly, people tend to prefer less choice to more choice. Research into consumer choice would indicate that Apple's offering of computers is more optimal than, say, Dell's. People look more when there is choice, but buy more when there is less choice. For more see Shah & Wolford, 2007 in Psychological Science.