Utilizing the ArcGIS API for Python, this examines items in an organizations ArcGIS Online account and offers details of their usage. It offers 3 datapoints to track usage: Usage in the last 12 months, Usage in the last 30 days and the date of last use.
"Use" in the ArcGIS API for python is defined within the API documentation below. It's definition varies for the various item types. Here is a shortcut to that verbiage:
"Depending on the item type, usage details can include the number of views, requests, or downloads, and the average number of views, requests, or downloads per day."
https://developers.arcgis.com/python/api-reference/arcgis.gis.toc.html#arcgis.gis.Item.usage