this "booster" was originally sold under the claim that "it's like adding a three foot antenna to your cell phone." well way back then... 5 years ago, cell antennas weren't that great to begin with and this little "sticker" did add a bit more reception to the cell phones of yore. nowadays cell antenna techonology has made antennas smaller and better... but not perfect. adding this "booster" to a relatively new phone won't add three bars to your reception... it probably won't even add one bar, but it does clear up your calls in areas where you have service. this thing isn't going to bend cell towers towards you to increase your calling area, it just holds the signal better in places where you can get service. if you live miles from a tower's sphere of influence this thing won't get you reception at your home, but it will make for a better conversation when you only have one bar.as far as i can tell, it does what it's supposed to do.