Instruct: Classify Amazon reviews into positive or negative sentiment
Query: DULL

Yes, we've all heard what hard work (no pun intended) making porn films is---that is a difficult job to remain excited and involved while the cameras are rolling. We've also heard about, and seen the evidence of, drugs in the world of porn. But who would have thought that the porn industry would prove as dull as work on a conveyer belt? Probst's book shows us this boredom in his, otherwise, excellent photographs. The story by A. M. Homes which serves as the book's introduction is merely pretentious.