Backup is always one of those beloved topics of system administration as nobody cares, but cries on data loss. This posting shouldn’t rate a method of backup – it should just introduce online backup as a way of doing things.
Online backup, as the name already says, happens online. In other words, your data is sent across a network – encrypted. To shorten the initial backup process, it can be done by manually carrying the data to the backup server i.e. on a harddisk (“Never underestimate the bandwidth of a station wagon full of tapes hurling down the highway” – Andrew S. Tannenbaum). The common backup process is done as a differential backup – only sending in the changed file.
Looking at a smaller office, this solution seems to be quite fine as long as the changed files are not too huge. The first advantage is, that you do not need backup hardware and that your backup is stored offsite in case it burns down. The backup service itself is replicated among multiple sites. So data loss should be as good as eliminated.
The only big issue I see are Bare Metal Restores as such a disaster recovery procedure would require either a copy of the backup or a huge download.