Stacksocial:

License purchased is good for 1 year of service, upon expiration, the Backblaze service can be renewed for $5/month or $50/year.

These services (Crashplan is another) are very dependent on the amount of data you have and your upload speeds but, if you can take advantage of it, it’s a good deal even at the full price. I always tell people you need multiple backups in multiple places. Having an online backup is an option for some.