I have had a tempurpedic matterss the past several years. In the summer it gets softer and a sink into it. Besides killing my back, I also have a cervical problemthat causes me to black out if I sleep completely horizontal. This pillow was just what I needed to wake up pain free in the morning. It molds into my mattress and fills in the sink hole and also raises it a few inches. It does this because it is made of the same material AND because it is long and tapered down to almost nothing at the edge. I could not find anything out there built this way. Definately worth the money!