Tokyo Pop
The site i choose to research is called tokyopop.. It is an american company that specializes in manga translation/printing. This website of theirs allows fans to post any manga related content in a wide variety of format. You can also purchase online manga to view, or download them into your mobile application.
1) Most people are here because they enjoy manga. Because it provides a platform to post illustrations, manga, blogs, avatars, fan-fiction, music, and videos(which is just a link off of youtube), people aren't limited to what type of medium to participate in. This allows users to post whatever they want. They are also clans that differentiates level of skills or manga style. Some clans specialize in only illustrations, while others focus on action genres.
2) This site has group communication in the form of clans. Most content seem to be completely public, though clans can be private and I think content posted in private clans are viewable within the clan only. Despite this, the participation remains extremely public, completed with shout-out. On a range from 1 to 10 with 1 being private and 10 being public I would call this a 7.
3) Right now there is too much information. The front page is organized into categories such as stars (something like super user), art (which is all about art/content), mobile (content for purchase), life (games, blogs, opinions, reviews), and hot (most popular user created manga). This makes it a bit confusing in the beginning to navigate, because when I look for manga in a bookstore I'm used to searching them by the genres (such as sports, martial arts). How important is star users in the manga world? I think if they eliminate the content not directly related to manga it would be much easier to navigate and easier for manga fans find what interests them.