Stop it, guys.
The glass has nothing to do with it. I have both glass and all wood humis. They are all the same except with the glass you open less because you can see your top shelf, and they look way cooler.
Listen to Culley. The problem is the way the President's humidifier is designed to fit in a wooden holder that stands up in the bottom of the humi. If you fill the top tray with sticks it reduces air flow to the top where the humidity is lost when you open the box. You need to leave some of the vents unblocked to allow the humidity to rise up from the bottom.
The way I solved this problem was to add a second humidifier to the top shelf, because I have too many sticks in there to leave vents open.
Redsquid is right. Glass is BETTER at containing humidity than wood is. That's why you never see liquids stored in wooden containers.