It appears BitTorrent solved the problem well enough. There's already an incentive to share, because nodes who don't are eventually ignored by the others (if I

It appears BitTorrent solved the problem well enough. There's already an incentive to share, because nodes who don't are eventually ignored by the others (if I recall correctly). As for the operating costs… they don't seem very high unless you're operating a tracker. I mean, it's just a matter of running a BitTorrent client, and not even all the time (unless you want to reliably seed something). The real problem there is the asymmetry of the bandwidth. If we had as much upload as we had download, we wouldn't have any reason not to shoot for a 1:1 ratio.