Versions are not backups. I wish I could find a simple web page that I read quite a few years ago. It very starkly explained why some things are commonly confused with, but just are not, backups. The consequences of those confusions are usually bad.
So, to all intents and purposes versions appear to act as backups, but you read a Web site a few years ago that said they aren't so that's what you tell people?
Not really. The concept of version works like backup for full fledge systems (SVN, git), but not what Dropbox exposes.
Dropbox keeps version of _existing_ files. You won't get back the files deleted and synched by mistake/misbehavior of some script. A backup would keep the files.
You'll also have different behaviors if you need to bring back a set of data (i.e. all your files as they were two days ago). You'll be in pain to do it file by file with Dropbox's version system.
A colleague of mine always says that you don't have a backup if a single nuke* can take everything away. So even with soft deletion, versioning in itself would not be a backup solution. OTOH, I'd bet Dropbox has distributed backups.
* An exaggeration for natural disasters, wars, lock-downs, fires and so on.
Dropbox keeps the history of deleted files just like modified files. Take a look on the web interface and hit the "Show deleted files" trashcan in the icons at the top.
Or for a different view, hit the "Events" link on the left navbar.
> Dropbox keeps version of _existing_ files. You won't get back the files deleted and synched by mistake/misbehavior of some script
Err, that is exactly what they provide. You do have to use the web interface to see them, and it is trivial to restore directories and files. (A bit painful if you want to only restore some of the files in a directory.)
