It’s part of the constant Marketing Barrage of large food companies. Someone in a "B" School, many years ago, coined the Phrase "Top of Mind Awareness’ & since then we’ve been bombarded. It was probably those Left Wing Conspiritors at HAAAAvard!
What’s even scareier is "University College London researchers have found the first physiological evidence that invisible subliminal images do attract the brain’s attention on a subconscious level. The wider implication for the study, published in Current Biology, is that techniques such as subliminal advertising, now banned in the UK but still legal in the USA, certainly do leave their mark on the brain."
Source: University College London
Date: March 9, 2007
Of course, this theory assumes we have a Brain!