I have a few qualms with this app:
1. For a Linux user, you can already build such a system yourself quite trivially by using Dropbox.
2. It doesn't actually replace Dropbox.
3. It does not seem very "viral" or income-generating. I know this is premature at this point, but without charging users for the service, is it reasonable to expect to make money off of this?
(Silly satire.)