I have no idea.I wouldn't even know how to test if they worked.
its obv a virus
i saw a richard for a split second, must eat richards, mmm sweet richards
Psychology recognizes them as valid. In a movie shown way back in the start of movie theater days, every hundredth frame they flashed a picture of the Coca-Cola logo and found that these people did indeed buy more coke during and after their movies.EDIT: It was coke, not popcorn. Coke was willing to pay them an assload for advertising so they didn't care whether it worked or not.
Why would you buy cocaine after watching an ad for coca cola? /joke