I'm going to work on this article when I get the chance, and here's a list I think it would need to cover to be complete (based on my experience):
- Alloy Entertainment property
- Books by Cecily Von Z. > response > spinoffs
- TV show > differences between show and books and fan response > Blake Lively as Serena was fancasting...
TV show fandom history:
- S1 response, NYM Recaps > Active fandom mostly at FanForum, TWOP boards, LJ > writers strike
- S2 ratings fell significantly, the show became less of a zeitgeist and more of a dedicated fanbase show. > Nate/Blair vs. Blair/Chuck shipping war and the filmed-both-ways ending of the season dominated fandom discussion.
- S3 Taylor Momsen leaves the show > migration to tumblr began > gganon (gg_anon?) became the most active GG community on LJ.
- S4 twitter became instrumental with how the showrunners interacted with the fans > fandom was preoccupied with a season-long script leak originating at fanforum (and twitter) and later IMDb > Dan/Blair vs. Chuck/Blair shipping war began > "Abusegate" after episode 4x20, Leighton's 2014 quote about the ship having some domestic abuse > there was more activity this season, it felt like a rejuvenation > gossip girl parallels
- S6 shortened 10 episode final season with dismal ratings > critical reception: find article about how Gossip Girl was out of step with the times. > criticism of Dan being gossip girl
- international popularity, particularly in china (actor appearances).
- graphic novels
- Gossip Girl: Acapulco in Mexico
- Alloy maintains the presence of Gossip Girl property on twitter and its site in the form of a Gossip blog, recent kerfluffle with Mindy Kaling: "wow you guys are dicks" over an article about her sense of style. (again with Gossip Girl being out of step with the times).
- Fashion (Target line, headbands and tights, Eric whatshisface the fashion coordinator's book, Blake Lively on Vogue, Blake and Leighton's fashion line spokesperson jobs)
- Shipping (dominated fandom discussion and activity, Blair/Chuck most popular followed by Dan/Blair and ?Nate/Serena?, list of other ships, in Season 1 slash fandom was active, "femslash unusually popular" with Blair/Serena. RPF about "Bleighton" and "Leighted" also very popular)
- TWOP forums
- Fanforum (spoiler thread and shipping threads especially)
- bleighton_squee (and the kink meme)
- gganon (deleted b/c of wank with gossipgirlsss)/anon_xoxo
- kink memes (3)
- gossipgirlnews (friended all the gg communities pretty much)
- gossipgirlsss (forum and blog) >> also the related secret community whose name I forget right now
- ggparallels (tumblr)
- Fanfiction (mostly posted to FF.N and LJ; AO3 was not widely used during the show's run, notable works?)
- Podcasts (after dark and the two guys who loved to discuss it whose names i forget)
- Other fannish works such as fanmixes, ...