Cell phone antenna boosters
Thanks for posting. This thread cooled off for a while.
My questions regarding your results are:
1. Are you doing anything else different now, such as not covering the sticker with your hand or perhaps you are closer to a window now than before? Any number of subtle things can affect the signal received.
2. Are you sure you are in the same exact position? It is easy enough to test your case using the signal strength bars on your phone. Place the phone in a fixed position (not your hand) where you feel the signal is "improved" by the sticker. Then try it both with or without the sticker and record the results in both cases. Remember, your body also affects the amount of signal received, so try to stay in the same position when you do the mesurement. This is a much better test than the uncontrolled situation you discribed, which really proves very little.