An Internet celebrity is an unemployed person, often a student, who is widely known among the members of an e-subculture or clique. The term itself is a lie because people who use the internet are not popular IRL. Most Internet celebrities have more friends on their LiveJournal friends list than anyone else, and it is to these vaunted heights of e-fame that all self-respecting attention or comment whores aspire.
Internet celebrities think that they are funny, witty and e-popular, but in truth most people just want to sleep with them. Some Internet celebrities mistake themselves for actual celebrities, but it is important to remember that even such individuals as Cory Doctorow are only known within a very small circle of Internets-savvy people. Get over yourselves. Kibo was one of the first Internet celebrities.