Which report will show me a list of when customers last ordered?
To see a list of when Customers last placed an order, use the "Manage Customers" page.
Navigate to the main menu. Click on the Customers sub section, then click on Manage Customers.
Ensure that the "last transaction" column is visible.

If this column is not displayed on the report, use the list icon, at the top right of the list, to add the column.

Now click the arrow on the column header to arrange in date order. With the arrow pointing downwards, the report will show oldest date to newest.
