Having your feeder on your window is an easy method to see your birds up close.
How to assure the suctions cups hold for a longer period of time: Immerse the suction cups in warm water for a few minutes. Then dry them completely. Then rub the side of your nose with your finger and lightly rub a bit of that nose oil onto the suction cup. Firmly stick the suction cup to your window.
Also, we have placed the suction cup on the glass from the bottom edge and middle and then top. Make sure there are no air bubbles