My presence on ArcGIS Online is small: Choptank River Heritage.
It runs on the Esri Home License – ArcGIS Pro and an Online site with 100 credits – for $100 per year. I use it to improve my ArcGIS skills while publishing historic maps to support my Choptank River Heritage volunteer blog about Caroline County, Maryland, history.
I was surprised to find that 7 percent of my annual credits were used up in the past 14 days, mostly for storage:
Storage of what? You have to drill down deep to find that. The help doc is here. The gist is: