Customers & Partners / CSA Members will show all members (even the ones with no current subscriptions.) In the middle "live" column, you will see number of current Active Subscriptions. The next column, "subs" is the total number of subscriptions since joining the CSA. You can click on either column title to sort the rows in descending order. The data from these columns can also be downloaded into Excel, that report will also include a date of the most recent purchase.
Home / Reports / Subscriber loyalty can be used to view Box Hold patterns. This might be important if you want to allow some member flexibility regarding box holds, but also want to monitor a farm policy of x number of holds limitation.