What AND-E said is correct except that monthly credit subscriptions can stack 5x* times your monthly sub.
For example, a Standard plan subscriber (400 credits) can keep a maximum balance of 2,000 credits.
Thanks @AND-E 
What AND-E said is correct except that monthly credit subscriptions can stack 5x* times your monthly sub.
For example, a Standard plan subscriber (400 credits) can keep a maximum balance of 2,000 credits.
Thanks @AND-E
