I know this may not be practical depending on the amount of space required, but you could probably run a very cheap EC2 image with a huge EBS volume attached fo

I know this may not be practical depending on the amount of space required, but you could probably run a very cheap EC2 image with a huge EBS volume attached for a year for cheaper than the bigger Dropbox offerings. For example, a micro instance, with 500GB of EBS storage, with allowance for 1% data growth per daily snapshot (S3 backed), and 50GB of transfer per month will apparently cost $175.68. The 500GB plan from Dropbox will cost you $499 . I'm thinking, with enough data, Bittorrent Sync wins the pricing war, and I've been doing some testing on the client and it seems really resilient to data changing while syncing etc.