With all due - I'd argue with the statement: "Computer Backup service is a backup, not an archive".
It's like saying that banking is a process of sending money to the bank but there is no guarantee that money will be there unless "customer is in good standing".
Computer backup is a process (backup) AND storage (archive). Without BOTH of these components in place the customers will be facing a big surprise down the road when their valuable data is not there.