Dark data is all the info your company collects but never uses—sometimes 60 to...

https://www.blaze-bookmarks.win/dark-data-is-all-the-information-businesses-collect-but-never-use-in-fact-1

Dark data is all the info your company collects but never uses—sometimes 60 to 80% of it sits inactive. It matters because storing and managing this unused data can cost millions each year, often $2.5 million or more