Online backup is part of our managed services portfolio, but is also a service that we provide independently of those other facets.  We can also set up a local onsite backup.  Ideally for the most secure backup and consistent recovery you would have both.

Data loss can happen at any time for a variety of reasons from electrical failure to user error to natural disaster to viruses and beyond.  You should ideally have multiple backups of any important data and online backup is great way to do that.  

There are several advantages to online backup.  One of the most obvious is that your data is not stored in the same location as your computer in case of theft or fire.  It is also less likely to be damaged than an external hard drive and will not wear out and fail like those inevitably do.