The best explanation I can give is that Gallagher has tapped into things that a lot of American manga fans like about manga, and they’re not necessarily the same things that make manga popular in Japan. For a lot of Western otaku, Japan fills the same function as Middle-Earth or Starfleet or twelfth-century England does for other flavors of geek: it’s a fantasy world where everything is attuned to their desires and, if they could magically get there, they wouldn’t feel like outsiders anymore. In this Japan, nerds are the ruling class, video games and comic books abound, cutting-edge high-tech toys flood the streets, and everyone dresses in cool, crazy fashions. And, of course, hot teenage girls fight each other for the right to hook up with introverted geeks. This fantasy version of Japan is seductive to a certain young, tech-saavy, socially awkward but culturally aware type — the type that increasingly dominates the Internet. Megatokyo delivers the fantasy in full: it’s about two American fanboys who move to Japan and, aside from some early fish-out-of-water difficulties, discover that it’s exactly the way it’s depicted in manga.

Shaenon Garrity, in “The Artistic History of Webcomics“, in The Webcomics Examiner.