Dark data is all the info your company collects but never uses—think emails,...

https://wiki-club.win/index.php/Why_Do_Companies_Keep_Data_They_Never_Use%3F

Dark data is all the info your company collects but never uses—think emails, logs, or old files. Surprisingly, 60-80% of data sits inactive, costing businesses up to $2.5 million a year in storage and missed opportunities