Celebrity - niche market celebrities,

One may argue that all celebrities are niche market celebrities, some niches are simply much bigger than others and many celebrities gain fame apart from their niche market as well.

A good example can be seen among the numerous professional athletes that are well known even among people who do not follow sports.

Celebrity - American comic book creators

American comic book creators are, for the most part, unknown outside of fandom as most popular American comics are still identified by their owning company such as Marvel Comics or DC Comics, instead of with a particular writer or artist.

Stan Lee (best known as co-creator of the classic Marvel superheroes) is mostly known to comic book fans and while in recent years, he has become more well known, many outside fandom are still unsure of exactly who he is, other than being a spokesperson.