One of the most useful uses of the Hair Part Theory is to both create commercials and/or explain their effectivness. The latest one is the charming Dad explaining about how is daughter will not wear anything other than her Princess Dress, even though it will get stained and dirty. http://great-ads.blogspot.com/2013/01/tide-and-dad-star-in-princess-dress.html
It’s a classic “new man” commercial, where the Dad is the one being the caretaker, nurturer and laundry do-er. So in the 30 seconds it takes to establish both the premise and message, they use a handsome right hair parting man to show an empathetic, kind, understanding (and domesticated) man. The right part makes it easy for the judgement to be quickly made by the viewer that it makes sense.