Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Sceptical..

Firstly, where is the evidence that robert grand's exercises does in fact make one grow taller?Secondly, where are all the positive reviews coming from?! Many are written in the same bad english, with vague claims of height increases. Some of them have simply PREPOSTEROUS claims of 6-7 inches in a year.Thirdly, why are all the negative reviews being rated as unhelpful? And all the positive reviews being rated as very helpful. Obviously someone is manipulating the reviews and ratings here.Mr. Grand, if that's his real name, is using the insecurity of short people and the anonymity of the internet to make money for himself. He's not even TRYING to help you. He's just out to take your money. Prove me wrong.