Dark data is all the information companies collect but never use—think 60-80%...

https://source-wiki.win/index.php/What_is_%E2%80%9CAI-Ready_Data%E2%80%9D_and_How_Do_You_Get_There_from_File_Shares%3F

Dark data is all the information companies collect but never use—think 60-80% of stored data just sitting idle. It matters because this inactive data wastes storage space and can cost businesses up to $2.5 million every year in unnecessary expenses