I believe that the idea of subliminal advertising is believed most likely do to the fact that it appears to the popular belief of psychology. Many, including myslef, have considered the possibility that we make decisions based on unconcious forces. In addition, many people blame unexplained actions on unconcious forces. Subliminal messaging causes these unconcious forces anf effect how they contribute to decision making. Also, if a person makes a decision with no answer, it is popular to believe there exists a reason for this such as subliminal advertisement.
I beleive the "witch trial" factor is the weakest. Although it does make sense that advertisers who use sublimial messages would keep it secret, it makes more sense that if it doesn't exist, there is no proof. This factor adds nothing other than the fact that neither side of the argument is correct
I never believed in subliminal advertising, because too many confounding variables exist to have commercials to effectively use them. Pratkanis did not influence my opinion, because many of his points were common sense and I already did not believe in subliminal advertisement. I do however believe that subliminal messages cn be used over time to generally change public opinion. This can be witnessed in any country including the USA.