I personally use Strongspace. Its a secure file storage solution which is accessible with a web interface or sftp and even rsync. Since the storage is built upon ZFS, it allows for some nifty tricks as multiple backups and even revisions. And did I mention that they use GiB? I mean, that has to be turn on for you folks. Here is a list of plans on offer, how you can put it to good use and some FAQs. Check it out!