Big Name Fan
From Fan History Wiki
Big Name Fan is a term that basically means what it says: A big name fan. It is a fan who is well known in his or her own fandom or across fandoms. The general consensus in the fan fiction community is that if you think you are a BNF, you aren't. As the number of fandoms has become bigger, and various shipper communities have become fandoms in and of themselves, there has been a growth of ship-community-only BNFs.
The term itself dates back to at least 1950 or earlier in the science fiction community. . Some lifelong fans such as Forrest J. Ackerman, Isaac Asimov, Ray Bradbury, George Lucas, and Steven Speilberg have developed followings of their own.
There have been several historical trends with Big Name Fans. In most pre-net fandoms, there were two types of Big Name Fans. The first type was the fan who had access to the 'powers that be' in the fandom. The second type was the fan who was the creator, publisher or organizer. As fandom moved on-line, a third type of Big Name Fan emerged. This was the Big Name Writer who was well known for their stories. There can also be Big Name Vidders, Artists, and otherwise, but the community general puts the greatest value on Writers as far as shaping the direction of a fandom, its fanon, and the types of stories regularly written.
In some fandoms, specifically the Doctor Who fandom of the 1970s and 1980s, Big Name Fans were the lust objects of the fandom as many of the actors on the show were older and not as attractive. 
- Big Name Fan. See SMOF. 
The following definition dates to 2005:
- BNF (Big Name Fan) - A fanfic writer who is famous either in the fandom as a whole or in a part of the fandom devoted to a particular theme, as a fan of your fanfiction. Basically, if one was a very minor author, yet JK Rowling happened to love ones work, then she would be your BNF. (Christ, I'm so clearly British, that whole sentence sounded snobbish) (Submitted by Madame Moi) 
- BNF: Big Name Fan. Any well-known fandom personality. These vary depending on who you're talking to, and what part of the fandom you're in at that moment. 
The following definition dates to February 2008 in the science fiction fandom:
- Big Name Fan; a fan of accomplishment who is not merely "well known" but "well liked" throughout the microcosm. It is important to note that, unlike certain other designations (e.g., "fan", "neofan", "trufan") one cannot legitimately claim BNFdom for one's self; to do so invites laughs of derision, since it's a term of admiration which must be applied to you by others, if at all. Because fandom is an anarchistic meritocracy, a BNF has status but no real power. 
The following is a list of some historical and current Big Name Fans based on fandom.
- Fandom Discuss: Big Name Fans by kettu_nainen on January 28, 2008
- Wherein Naphy Somehow Ties Fandom to Howler Monkeys, Underwear, and Celery by anaphalis on January 30, 2007
- Fanfic Symposium: Nobody Ever Admits They're a BNF by Hope in July 2005