In the opening scene of Psych Season 4 Episode 10, young Shawn Spencer is sitting around watching tv when his dad comes in and berates him for sitting on his butt instead of going outside. At the time, a very effective ad comes on, and his dad asks, "What does that make you want to do?" with the flashing words "Join the Army" on the screen. Shawn answers "Go into advertising."
Advertising doesn't always send people running to buy your product, though there are notable exceptions, but a fun, catchy ad certainly stays in your memory. I've had more conversations than I can count recounting particularly funny Super Bowl and NFL Playoffs ads. What all this means, of course, is that if what you're trying to advertise is simply awareness, then a catchy advertisement could be pretty effective.
According to Dawn Walton's article in The Globe and Mail today, Alberta has been effective in advertising syphilis. Their advertising campaign essentially mocks dating ads and has led to 1,139 more people visit clinics for sexually transmitted diseases. I wonder if the ads would've had the same effect if they'd taken a more sincere tone. It's possible that America's had advertisements of a similar tone, but I certainly haven't noticed them. It seems that the US is more "PC" when it comes to these things; that was certainly my impression in high school when we watched driver safety ads from the US and from Britain.
Here's the website for anyone who's curious.