The pricing model doesn't make sense to me. Their prices start at $0.025/GB/month, so renting 1TB of storage for a year would cost $300 - at that price, I could just buy my own disks and run ZFS myself. I kinda hoped they could offer lower prices using economies of scale. I checked the prices for Tarsnap, expecting it to be cheaper - it's actually 10x more expensive! Maybe someone can explain what I'm missing.
I came to the same conclusion. I was aware of rsync.net and tarsnap, and have checked their prices in the past, but for raw storage it's simply not competitive. Some of the other features they offer might make it worth it though if you need those.
Personally i just need a place to dump a backup of my family photo albums and documents. A full backup is around 1TB (deuplicated, somewhat larger raw), and for that there are much cheaper solutions.