Instruct: Classify Amazon reviews into positive or negative sentiment
Query: This worked for me, and obviously others.

Just looking at all of these comments confirms that I am not the only one- this book worked for me as well. I used to have a problem maintaining an erection, and I tried it all. Pills, docs, herbs, diet change, exercises, you friggin' name it. I read this book though, and tried out the tips inside- absolutely amazing. Don't take my word for it though- try it out yourself.