How common and effective are subliminal messages in advertising?

Subliminal advertising – which plays on the theory that “one can influence behavior by secretly appealing to the subconscious mind with words, images, or sounds” – enjoyed widespread use in the past fifty years, but is clearly a controversial topic today.
Is this type of advertising that features sexual or other hidden messages ethical, especially when targeted toward the younger generation? I think not.
In my opinion, customers' subconscious minds shouldn't be influenced or "manipulated", without their awareness, to respond to certain messages.

Well, if you're asking weather they are effective and successful or not: the answer would be definately they are! However, if you are wondering about ethics: well, i'd simply say that the common/only drawback/disadvantage of capitalism is that it's self-motivated towards personal benefits and personal interests regardless of anything else; whether this message/advertisement is ethical healthwise, or promoting certain sexual, social or even political ideology, it certainly doesnt matter(and never will).
Not that i'm with that, but it's the painful truth!