How do I customise Affiliate payout

Liking this plugin! But can't see how to set it up how I want it. I don't want to pay for clicks, sign ups and have no paid members.
I sell a monthly subscription for a service and would want to pay on a successful referred sale. Probably on the second or third renewal.
is it just a matter of changing the field to say what I want and blanking the other two. Can't see how to customise this.
david