Dark data is all the information your company stores but never uses—like old...

https://domgodwinson38.gumroad.com/p/how-much-of-enterprise-data-is-usually-inactive

Dark data is all the information your company stores but never uses—like old emails, logs, or files gathering dust. It can be up to 60-80% of your data, quietly eating up storage space and costing you money—sometimes $2.5 million a year