Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Worth every penny!

My son was almost 6 when we purchased the alarm and our goal was to have him not wetting the bed by his birthday. He was very enthusiastic about using the alarm (which I think was a huge part of its success). Within a week he was waking up before the alarm even went off to go to the bathroom. He had a couple more nights when the alarm went off and went to the bathroom on his own. And he was not wearing Goodnights anymore on his 6th birthday!!!