Instruct: Classify an Amazon review into positive or negative sentiment.
Query: beware of rebate scam!

On the rebate form they provide a place to cut out the UPC code and a place to write the serial number. Then they reject the rebate claiming that you're supposed to cut the serial number from the box too. Probably, the clearest/most obvious rebate scam I've ever fallen victim to. DVD player still works mostly, but I would never trust this company to buy anything else.