Instruct: Classify Amazon reviews into positive or negative sentiment
Query: Air matress

Shipment #1: Shipped on December 4, 2010 Queen Raised Air Mattress Day Bed w/ Quilted Air Pockets & Built-in Inflation Pump.Yes they want us review it the day we recieve it !! It was nice the first day, till March, then a big bump in the middle of the matress developed. I regretfully thought it was a bad matress, so I bought another. Guess what, same thing happned. Not a bad matress, just another cheap company, trying to make money off hard working Americans !