The primary use case is for disaster recovery to back up the infrastructure, e.g., ESX backup. If there are any problems, We can restore quickly or live Boot the most important VMs and get back working in a very short period.
We have deployed an appliance in house (on premise), which backup our local servers. We have virtual servers running on VMware ESXi. Our Backup includes backing up the VMs separately but also backing up the ESXi completely.
We have a second virtual appliance running on a separate system which we use as our secondary backup platform.
We also have Cloud replication which is done from our on premise appliance to Barracuda Cloud.