For example, consider a typical comment on a YouTube review video about a Motorola Xoom tablet: this guy really puts a negative spin on this , and I 'm not sure why , this seems crazy fast , and I 'm not entirely sure why his pinch to zoom his laggy all the other xoom reviews The comment contains a product name xoom and some negative expressions, thus, a bag-of-words model would derive a negative polarity for this product.
the opinion towards the product is neutral as the negative sentiment is expressed towards the video.