I've used Dropbox for years, primarily to transfer files to and from clients. But I only have 20GB -- not enough for backing up significantly without paying for more.
However, yesterday I transferred a file to Google Drive, which I never use, because Dropbox had gotten a bad copy of the file and kept reloading the file from cache rather than creating a new version. While in Drive, I was told I have 117GB available! Son of a gun! Where did all that come from? Or is Google just really, really generous with their free storage?
Anyway, point is, now I'm considering using Drive for backups.

Ha! Me too -- though I don't have full Office for all versions. I have Access 2.0 (or 3.5" floppy disks!), from 1996, and then every version of Access and most versions of Office after that. I currently only have Office 2003 forward loaded on my machine, and will probably not even load that on my next machine.