"Advertising may be described as the science of arresting human intelligence long enough to get money from it." Stephen Butler Leacock
I'm pretty sure that the product being advertised DOESN'T have the advertised side effect, but I'd be tempted to try it...just in case!
Since the ads that work best usually work at the emotional level, there are few emotions more powerful than lust, which probably explains the prevalence of sex in advertising. A few links providing collaborating evidence:Blush LingerieFighting 'Em Off Hai Karate StyleHot Slutty Animals Selling CarsHistory of erotica in advertising