How does your system handle large files? I have a 20 GB encrypted TrueCrypt volume that I put inside my Dropbox folder. It does syncs of up to 4 MB chunks at a time, when I dismount the volume. It did take me a few days to upload the fresh volume on initial sync.
Thanks a really good question. Our software has some very sophisticated detla code. I like to explain it using a 100 page word document as an example. Like most software it can run a diff on the version it had before and the current version. So, if you opened your 100 page word document and changed a single letter in it, only that letter would be uploaded. More importantly though, if you moved a paragraph from page 32 to page 3, the software would NOT re-upload the whole paragraph. And thats really the question, I'm not entirely sure that our software would be able to recognise the changes inside an encrypted volume file. It really depends on what a change in the volume "looks" like in the binary of the file. But, 20GB files are no big deal. Some of my clients are running databases 10 times that size and we have no issues backing them up. We even have clients backing up full 1TB+ system images and our software performs like a champ for them. You've got me intrigued now, I'm going to have to try that.
Thanks for your pricing ideas!