Dark data is the information companies collect but never use—like old emails or...

https://future-wiki.win/index.php/What_Should_a_5-Step_Dark_Data_Action_Plan_Look_Like%3F

Dark data is the information companies collect but never use—like old emails or forgotten files. It makes up about 60-80% of inactive data in organizations, quietly taking up space and costing businesses around $2.5 million every year