To bring home the message that smoking is bad for you, Ogilvy Thailand turned the tables on cancer stick suckers: Rather than try and convince them to quit by telling them how bad smoking is, the ad agency instead tricked smokers into telling themselves how bad smoking is by having them try and convince a child not to smoke.

Simple, yet, if the PSA is to be believed, effective: The Thai Health Promotion Foundation saw a 40% increase in phone inquiries from smokers who wanted to quit.