Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Memory Foam Topper

I have a Craftmatic adjustable bed and the mattress has gone old to the extent that it started to hurt my back. I was not able to sleep on my back. For years, I have been searching for a good mattress.After reviewing so many good reviews on Amazon, I decided to order this mattress topper earlier this year. After using it for eight months now, I must say this is probably the single best purchase I made on Amazon. I am now able to sleep on my back. Great product.