I just took delivery of my gum order from Amazon.com.
I scheduled 4 boxes/month, WAY TO MANY; so, I tried to change it to one box per month. The system wouldn't let me, read no fewer than 2.
So, using my hard scrabbled university logic, I set the order to two boxes. However, I set the delivery to every 2 months. Averages to one per month. BOOM.
I enjoy besting the machine.