Product Family: Act!
Product: Act! Pro, Act! Premium, Act! Premium (access via web), Act! Premium Cloud
Version: v16 and up
Integration: Act! emarketing
Yes. You can upgrade your account to any service level you would like and downgrade whenever you are ready to do so. For more information, please see the following article:
How do I upgrade, add, or remove features from my Act! emarketing account?