Dark data is the information organizations collect but never use. It can be 60...

https://www.bookmark-zulu.win/dark-data-is-the-inactive-or-unused-information-stored-across-your-systems

Dark data is the information organizations collect but never use. It can be 60 to 80% of your stored data, sitting idle and costing companies up to $2.5 million a year in storage and management