Dark data is all the information companies collect but never use, often making...

https://mag-wiki.win/index.php/What_is_Data_Curation_and_How_is_it_Different_from_Data_Classification%3F

Dark data is all the information companies collect but never use, often making up 60-80% of stored data. This inactive data can cost businesses up to $2.5 million each year in storage and management fees