Crashplan+ Unlimited is USD 2.92/month if you take the 4 year package. When I upload 300GB to Amazon and pay 0.01 * 300 = USD 3/month. Amazon would be even more expensive for larger amounts of data.
Is there some fine print I'm missing with Crashplan unlimited?
What's exciting about this, is that Amazon doesn't care _how_ much data you send them - presumably they've priced this so it's profitable at any level you wish to use. It's a sustainable model. Services like TarSnap/Arq will likely adopt this new service (Possibly offering tiered backup/archival services?).
I have (close to) zero doubt that Amazon's Glacier Archival Storage will be available 5 years from now at (probably less than) $0.01/Gigabyte/Month. They are a (reasonably) safe archival choice. Now that light users (<300 Gigabytes) have a financial incentive to move off of CrashPlan onto Amazon - it further exacerbates the challenges that "Unlimited" backup providers will face. All their least costly/most profitable may leave (or, at the very least, the new ones may chose Amazon first)
With that said - I love Backblaze (Been a user since 2008) for working data backups, rapid-online (free) restores - and I will continue to use them, but I wouldn't plan on archiving a Terabyte of Data to them for the next 20 years.
http://blog.kozubik.com/john_kozubik/2009/11/flat-rate-stora...
They put the provider in an adversarial relationship with the user and give them an incentive to keep you from storing data there. They will make it hard for you to use their service.