Answer: subliminal

AnswerCrossword Clue
SUBLIMINALKind of subtle ad technique
SUBLIMINALKind of TV ad technique
SUBLIMINALLike underhanded advertising
subliminalinadequate to produce a sensation or a perception / a subliminal message
subliminal(of a stimulus or mental process) Below the threshold of sensation or consciousness; perceived by or affecting someone's mind without their being aware of it