sorry but how is $10 a month a good deal per TB for backup (especially when they will charge you extra for restores). it may be more convenient but it is still way more expensive then do it yourself solutions such as backup and store at a friends house. In a 2 year period you are paying 5-6 times what the storage actually costs, more that money there are far cheaper and better solutions. myself and a friend provide hosting for each others backup data (onine), costs us a tiny fraction of what Amazon or Google charge and we get to maintain control of our data.
I think you just answered that -- it's more convenient (and it's automatic).
Soon after adding new photos to my NAS, they are backed up on Amazon, no need to remember to do a drive exchange with a friend across town.
If I have to do a restore from my Glacier backups, then that means that both my NAS and backup drives have failed, so I've had a major catastrophe (and in the event of an earthquake it's likely that the friend across town is suffering from the same catastrophe). So in that case, I really don't care if I have to pay a couple hundred dollars to do a restore.