When it comes to improving health, there are carrots and there are sticks. One way to try to influence people's habits is by tying how much they pay for health coverage to their behavior. Starting next year, for instance, Wal-Mart, the nation's largest private employer, will charge workers who smoke a penalty ranging from $260 to $2,340 annually on health insurance. That's a pretty big stick. As for a carrot, the retailer will offer free smoking-cessation help. Across the country, employers are rewarding some workers, such as those who exercise, and penalizing those who are overweight or smoke. We wondered how that approach is going over, so we asked more than 3,000 adults across the U.S. in the latest NPR-Thomson Reuters Health Poll.