You are provided download access and priority support for any extensions you purchase for as long as your subscription is valid. After the subscription expires, you are free to continue using the extension for as long as you wish, on as many sites as you wish. However, you won't have access to new releases if your subscription expires.
Please feel free to check out the subscriber FAQ below as it should have this, and other answers, you may be interested in:
www.sourcecoast.com/extensions/subscription-faq 
JFBConnect upgrade
