Was thinking about Product Placement the other day and the strategy needed to optimally place a product in a TV show. (I've been watching a lot of films recently and although placements in movies are a much more mature channel I've been a bit surprised (and even offended) at how blatant some placements are.) See Jake Gyllenhaal's watch in Source Code as a good example of something that's a little too blatant IMO.
You see, if there's an imbalance from any of the three stakeholders I don't think the placement will be successful.
Let me explain:
From a Brand point of view, you have to select the most relevant show for you and you have little control over how the product is placed (whether your chocolate bar will be eaten by a nice person and praised, or spat out by the bad person who says it's horrible); you have to be sympathetic to the TV Scriptwriter in the same way Planners are to Creatives (make them believe the product adds something to their show, not denigrates it in any way); and ultimately so the End Consumer doesn't have their viewing experience ruined by the product. If your chocolate bar is out of place, commands an inordinate amount of screen time or focus or breaks their vision of fantasy and reminds them it's just a TV show - then you're in trouble.
But, if you balance these three things out successfully you're on your way to placing a product in the way it should be.