I purchased the Shake Weight and I absolutely love this product! I had read a couple of reviews where people stated that it didn't work for them, still it has worked great for me and definitely worth the $20 that I paid for mine. A person should follow the video to get maximum results from the product and one does need to put some muscle into it when working out with the Shake Weight. After I began using mine I noticed that the more you make your arm muscles work the more they respond just like with any other muscle in the body. Another thing that I love about the Shake Weight is that it's only a 6 minute workout and it works on the right muscles to get that firm, toned look again.