Well, except some degree of redundancy would be built in to the storage scheme á la BitTorrent.
As far as data volume, I've got to imagine the data usage per user would be significantly less than BitTorrent.
The desirable aspect of this system is obvious - the only people who see your data are people who've seen a QR code from someone in your social graph - your FaceTorrent profile will never, ever be indexed by Google.