In ArcGIS Online administrators can view the status of their credit usage and other things like the organization's content, apps, members and groups. However, there is no information about the storage size of the items. As item storage costs credits it would be useful to see the size of the items. Based on that information items that take a lot of storage space (and therefore credits) could be deleted. It would be helpful if an extra column could be added to the item table (Content tab) with the item's size.