When DSL and cable first arrived, ISPs abandoned the per-hour dial-up access billing model for unlimited bandwidth at a flat rate fee. Recently, Comcast has come under fire for “shaping its traffic” (read: blocking) while maintaining its unlimited contract with users. Lawsuits have been threatened and the FCC has been stirred to comment. The issue at hand is the peer-to-peer file sharing networks. While their user bases account for a very small percentage of the total Internet audience, the traffic they generate is said to account for anywhere between 50 and 90 percent of all data.

A: One critical difference between the Web and TV is how they scale. TV scales nicely—it costs the same to air a show to 10 viewers as it does to a million. On the Web, distributing a file to a million users at once is nearly a million times as costly (and slower) as delivering it to one.


BitTorrent, an open-source peer-to-peer parallel downloading tool written by Bram Cohen, changes the equation: The more popular a file is, the easier it becomes to fetch and the cheaper it becomes to serve.