I would like to add that this can be customised for additional various components, such as minimum orders met e.g. ordered 1 and requires 2 to be met and be logic based for some more advanced versions of this, e.g. customer purchases something for x dollars every 30 days, you require 7 days notice, so it takes the ammount charged for a 30 day / 7 and this is charged for cancellation so on and so fourth for closely related solutions.