I have some featured services in Portal and if I look at my credits usage, I am burning 25-33 credits per day, just on storage. Looking at the documentation for understanding ArcGIS Online credit usage, it specifically says for Feature storage, excluding feature attachments, that it costs "2.4 credits per 10 MB stored per month, calculated hourly". What am I missing here, if I'm being charged daily when the documentation notes a monthly charge? Am I reading this wrong?