I am currently storing 9 GB of family photo images on S3.
Total cost per month?
So why would I use one of those 3rd party backup services?
And yes, before you ask, there are ways to script file uploads, even on Windows. In fact Amazon supports their own take on rsync for that (the open source AWS Cli, that can be installed with an .msi for Windows or with python pip on Linux).
But Windows being as unreliable as it is, and the availability of a given Windows machine being unpredictable, what I actually do is backup to S3 from my home Linux server. I’m currently experimenting with a few different tools to get the bits off the Windows machines and onto the server, including Bittorrent Sync.
The main problem there is that scheduled backups aren’t an option. What really is needed is a solution that starts backing up when the machine starts and keeps it up until someone does a forced shutdown. So far Bittorrent seems to be able to handle that, but sync solutions on Windows scare me for everything that can go wrong.
There’s also the question of using encryption for documents I want to keep safe but also private. I wouldn’t use that for family photos, but definitely would need to for scanned copies of tax returns. Thanks to the fact that I’m funneling everything through a Linux box, there are a lot of options for that (Amazon’s unified AWS sync tool doesn’t support client-side encryption, but the open source third party s3cmd does).