Why Twitter is a big deal [2009]

Paul Graham's essay argues that Twitter matters because it is a new messaging protocol in which the sender does not specify recipients, and new protocols that catch on are rare. He notes that TCP/IP, SMTP and HTTP are among the few commonly used protocols, and that Twitter is unusual in being owned by a private company. He suggests the founders' slowness to monetize may help it, since Twitter feels to users like earlier open protocols and its private ownership is easy to forget.