If you haven't heard of it, Storj is essentially a distributed S3 that's been around for many years now, and the way it works is that various people run Storj nodes while the Storj company runs a proxy server that breaks files up into small encrypted chunks and stores them across N peers for redundancy.
In my case, I back up my family photos/videos/documents to a Synology NAS, and my NAS is backed up to Storj. So when I run a Storj node with part of my disk space, the payments they give me essentially cover my own backups. I'm not making a ton of money or anything, but it's enough to pay for my own backups and that's a great deal.
If you're looking to do what the OP is talking about in a simple way, this is by far the best way I've found to do it.