I've been wearing my armband for a week now, and I think it's great! I paid $150 at Costco, and it comes with a one year membership. It measures your calories burned, your steps, and the quality of your sleep. It's a constant reminder to move more. You upload the data to the web site every day and compare it to your calorie intake. I use my Spark people Nutrition page and then fill in the calories on BodyMedia.