When a server, SAN array or a batch of drives reaches end-of-life, the hardware retirement itself is the easy part. The part that gets businesses into trouble is what's still sitting on the disks — customer records, financial data, credentials, internal documents — none of which goes away just because a file was deleted.
A normal file delete (or even a quick disk format) only removes the filesystem's pointer to the data — the actual bits stay on the platters or NAND cells until something else overwrites them, and can often be recovered with off-the-shelf data-recovery software. For any server that ever held real business or customer data, this is not an acceptable way to retire hardware.
Enterprise hardware retains real resale value even after it's wiped — CPUs, RAM, drives and chassis can be responsibly refurbished and resold rather than landfilled, provided the data-sanitization step happens first and is done properly. That's a genuinely better outcome than either sitting on retired servers indefinitely (a security liability sitting in a storeroom) or scrapping hardware that still has years of useful life left.
We buy back retired servers, storage and workstations with data-sanitization handled as part of the process, and issue documentation for what was wiped. If you're replacing old hardware with something newer, ask about our exchange & upgrade program — trade in the old unit for a discount on a tested, warrantied refurbished replacement.