Instruct: Classify the given Amazon review as either positive or negative.
Query: Paid for Themselves!

I live in the Rockies of Colorado in an all electric house. My monster central furnance helped create a $300 a month electric bill. I purchased three of these units - one for the bedroom, one in the living room and one in the kitchen/dining area. My electric bill immediately went down to $180. Needless to say, they paid for themselves in just a couple of months. They are very reliable, give off a nice subtle heat and are very quiet. I am quite pleased with this purchase.