Average Orders per Month measures the number of orders from customers you've received on average. It can be used to estimate your order volume and is useful to predict upcoming months.
Since the number of orders can fluctuate from month-to-month and over a year's cycle, it is useful to use at least a year's order data. That will allow the averaging to smooth out any highs/lows.
Eric Davis
How do your products determine customer behavior
In Repeat Customer Insights the Customer First Product analysis will measure customer behavior based on the products each customer first ordered.