Digital Ocean is a solid hosting service but backups only take place once a week. If you have a crash or lose an entire server as can happen then clients could lose up to a week's worth of transactions.
Fortunately Amazon S3 is almost free and it's not difficult to set up backups.
There's an excellent tutorial here that can almost be followed step by step, however we'd recommend using a newer version of s3cmd. The version available via apt is outdated and is missing some of the most recent command line options.
To install the most recent version:
sudo apt-get -y install python-setuptools
tar xvfz s3cmd-1.6.0.tar.gz
sudo python setup.py install