I don't mind product placement when it's done well enough to feel natural. The kind I do have a problem with is when it becomes part of the plot, like say, an episode of a TV show written around it, characters interacting with it and even speaking its name out loud. Like for instance, one TV show had the character shopping for a new car and was all excited about the self-parking Ford Focus, mentioning all of the features they had on the car and showing the character engage the self-park. They used a whole scene of about 5 minutes for this. Another episode of the same show had them using lipton ice-tea packets, mentioning them by name and acting all impressed.
I think that product placement works best when it's subtle. If it's too obvious, it can have the opposite effect.