Your credits roll over from month to month and are based on how my active prezzos you have in your account.
If you have a Standard subscription with 15 credits per month, and you have created 10 in your first month, you will still have 5 credits in your second month. You don't need to delete and create new prezzos for the ones you have, just update the stats with the latest figures.
If you want to create new prezzos but have reached your limit, you can delete old prezzos from your dashboard to immediately gain new credits, or upgrade your plan to include a higher monthly limit.
Any deleted prezzos appear in the bottom section of your dashboard page. You can re-activate them at any time, but this will impact your credits.
Only active videos can be shared using the url.