Informing, begging, threatening, and shaming are all being tried to increase the number of people who wear masks. How about rewards? Any preschool teacher can tell you that students clean up faster if a teacher circulates around the room giving stickers to kids who are doing their jobs. Even though it seems ridiculous to reward people for doing the bare minimum to protect their neighbors, I think incentives will have some effect and save some lives. Also Americans enjoy gamification. I think if undercover agents gave out $100 gift cards (or even $1000) daily at random to people wearing masks in public places it could entice a segment of the population to do it. The program would pay for itself in terms of the lives, virus tests, and hospital time saved. It could save the lives of cashiers and other people who are forced to interact with the public all day. Also, any increase in mask wearing can have a positive feedback effect. The more people see others around them wearing masks, the more likely they might be to do it themselves. This will not entice the most die hard anti-maskers to wear a mask, but it could entice some of the people who don't know what to think because they are getting "information" from both sides.