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
Get a snapshot of your customer behavior
The sooner you signup for Repeat Customer Insights, the more comparison points your store will have. Each 1st of a the month a new snapshot is taken and saved to your account for analysis.