Dark data is the info companies collect but don’t use, often making up 60-80%...

https://source-wiki.win/index.php/What_is_a_Global_Metadatabase_and_Why_Would_I_Want_One%3F

Dark data is the info companies collect but don’t use, often making up 60-80% of their stored data. It matters because keeping this inactive data costs money—some businesses waste up to $2.5 million a year on storage and management