I now “get” BitTorrent. I had to check it out when someone at the IETF sent out a BitTorrent utilization graph which shows the awesome speeds possible.
Its success is mainly due to its politics, not technology. The longer you stay on (dependent on the tracker), the better your download speeds can become. Implementations do not take you to a “default” server; you have to go find a torrent link, meaning that BitTorrent can’t be held at fault for any copyright violations.
I’d like to read a technical specification to figure out who tells the BitTorrent tracker that you’ve got credit. Could I set up two BitTorrent machines that connect to the same tracker, and have one machine give credits to the other machine?