One side-effect of all these commercials is to shorten the attention span of viewers. I feel that kids are taught to only get into a thought/storyline for a maximum of 8 minutes then switch mental contexts 4 to 8 times before returning to that original story. While I have no evidence about it, I don't see how this can be healthy. In contrast my children watch shows with episodes ranging from 12 minutes to full-length movies of 1h30 without interruption.