I take a lot of photographs. And each one of those photographs I save in RAW format to preserve the original integrity and allow me to easily edit the photo in the future.
The byproduct of that is that I need a lot of storage space, and I mean a LOT! Each photo is about ~ 25 MB. Compound that times 100s of photographs I might take at an event, and we're easily talking Gigabytes for one event. Luckily, I have a Mac Pro which lets me keep 4 hard drives with over 3 TB of storage. Two disks are configured as a RAID 0 array for maximum performance. The other two are set up as a RAID 1 array for redundancy, and I use Time Machine to backup the first array.
However, what if my computer were hit with some natural disaster or stolen from my apartment?! I would lose everything regardless if my data was backed up in Time Machine. That's why I signed up for Backblaze.
There are a couple of different services out there that do this, but I think Backblaze does it best. It's dead simple, installs as a lightweight daemon that I've observed uses very few of my precious resources, and does it very cheaply. You can sign up for $5.00 a month or pre-pay for 2 years and get a big discount.
I trust Backblaze because I know their hardware. They blogged about how the built up their storage system.