"recommended"
As I recall I said something like 'I've never used a window feeder, but here is one that my boss uses.'
Sometimes it takes birds a while to find a feeder...especially if there are no tree around. So here's a thought, occasionally use your phone to play a chickadee song and calls our the window for a minute or two. That might help them notice the feeder. You're up north right? so use the black capped chickadee calls here: https://www.allaboutbirds.org/guide/Black-capped_Chickadee/sounds
or try a Tufted titmouse call: https://www.allaboutbirds.org/guide/Tufted_Titmouse/sounds
