Hence why nearly all of them have disclaimers saying so. Advertising is inherently deceptive... it always has been and always will be. But that doesn't mean there aren't stupid people who believe it. Nobody thinks the Trix rabbit is going to pop out of a box of cereal because General Mills doesn't claim that will happen. People do expect (or, again, delude themselves into hoping for) magical transformations. It's what drives almost anything cosmetic, from makeup to skin cream to weight loss supplements.