Yes, and DynDNS too. Which is fine, cause it works, and that is what I said. The claim to which it replies is that people have to pay to Dropbox cause poor souls were stopped from sharing files using existing technologies like FTP by the damned IPv4, and not because they simply prefer an out-of-the-box GUI thing.
Relying on peer-to-peer relays also doesn't scale, which is why Skype dropped its supernode architecture.