Saw this on Android Police:
[Deal Alert] Get Unlimited Mobile Cloud Backup From IDrive For $10
Basically you pay US$9 (price is US$10, but then you use "HAPPYCM10" code for an extra US$1 off).
You are supposed to get "unlimited" backup for "life". Lets see how either statement stands the test of time though. I do already have the likes of Dropbox, Google photo sync, etc, but all of these have a finite storage limit.
I decided to sign up as I think it would be a good way to back up videos and photos on my phone. The app itself is pretty basic and nothing compared to Dropbox or Google drive, but it allows for scheduled backups and should be fine for a purely backing up solution. Also IDrive claim that all the data is encrypted.