I might have said this before but it was mentioned by a couple of MSP's at the agent show that I am at. The key to data backup is not backup but restore. The piece that many staffers miss is validating that the tape backup ran correctly and that the tape itself is without damage.
Back in 1996-1999, I worked for a Novell VAR and HP tape backup was at every client site. Despite that, no one checked the reports even for the warning that printed out about the tape cartridge being locked or that the backup had an error. They found out when the server hard drive crashed.
Hard drives crash. Not maybe, but when. Backing up data, especially sales and client data, is essential to the continuation of your business after a crash (or other adverse incident).
When you are offering Data Storage -- and you ARE selling backup, right? - remember that the key to sales isn't the backup, it's the validation and retrieval. (off-site too).
Also, when selling backup, mention that you are not displacing bodies but making them more efficient and giving them some time back from this mundane but essential responsibility.