Fannish Drift

The term Fannish Drift can refer to several types of situations. 
==Types of Fannish Drift==
===Vocabulary drift===
Fannish drift is the tendency for the definition of fannish terms to change over time. For example, a new fan may see the term PWP listed on an archive, and not have any idea of what it means. Over time, that fan will derive a working definition of what the term means based on what they read that was labeled in the given manner. That definition may or may not include all of the components that the 'currently accepted definition' would include.
For instance, many fans see very short stories called drabbles, and go on to call any very short ficlet a drabble, whereas others fight to retain the original definition of a drabble as always being 100 words, no more, no less.
===Fandom drift===
The gradual shifting of a fan's primary fandom(s).
There are many reasons why fans move from one fandom to another fandom.
Spin-offs, sequels and adaptations of existing properties often begin with a "built-in" fandom, made up of fans of the original source. Examples include:
* Doctor Who, Torchwood and The Sarah Jane Adventures
* X-Men comics, the original X-Men Movieverse trilogy, and X-Men: First Class 
These fandoms may or may not capture or ultimately retain the goodwill of a majority of fans of the original source. For instance, many fans of Highlander were disappointed that Highlander: The Raven was not more like Highlander, and many Stargate: Atlantis fans actively resented Stargate: Universe, blaming it for what they felt was Stargate: Atlantis' premature cancellation. 
They may follow creators; for instance, there is a lot of fannish overlap between Aaron Sorkin's Sports Night and The West Wing, although Studio 60 on the Sunset Strip failed to build a similarly large or active fandom. Many fans followed Joss Whedon projects after Buffy the Vampire Slayer, going on to become fans of Firefly, Dollhouse or Dr. Horrible's Sing-Along Blog; some followed him to Marvel Comics during his arcs on Astonishing X-Men and Runaways.
Fans may follow a shiny new BSO; when fen discover new focal points for their obsessive tendencies, they often begin tracking down every movie, short film or tv show that said BSO has ever appeared in. In some cases, this can lead to the birth of a brand new small fandom, like an offshoot from the main fandom. 
Sometimes fans "follow" actors back throughout their filmography, discovering failed pilots, obscure made-for-tv movies, arty short films or short arcs as recurring characters on other shows. On occasion, small fandoms have gotten a boost of interest due to actors who appeared on them suddenly becoming fannish favorites. (For instance, fans of BtVS' Anthony Stewart Head may track him back to his role on VR.5, or fans of Jensen Ackles on Supernatural may follow him back to Dark Angel.)
Other times, a side project (perhaps a film shot while an actor's tv show is on hiatus) may emerge as an offshoot fandom while the main fandom is still ongoing. Most of the time these "spinoff" or "offshoot" fandoms remain obscure, existing mainly as a subset of the original fandom. (There may be a substantial number of crossovers between the "parent" fandom and the "child" fandom; these are often popular in the Hewligan genre of SGA/offshoot fandom pairings.) 
Some "offshoot" fandoms, however, develop enough activity enough to draw attention even from "outside" the original big fandom, and become relatively self-sufficient, independent fandoms; many 6 Degrees of Canada fandoms have achieved this. Another example would be Cabin Pressure, a BBC radio comedy discovered by many fans of Benedict Cumberbatch after the actor became a fan favorite from Sherlock, which then became an active small fandom in its own right.
Finally, after a show or film is over, if a fannish BSO moves on to a new show, many fans will follow them; for instance, many Man from UNCLE fans were thrilled that Robert Vaughan once again had a starring role on Hustle; Eliza Dushku fans from Buffy the Vampire Slayer fandom at least gave Tru Calling a try, and some Farscape fans gave Stargate SG-1 a shot after both Ben Browder and Claudia Black joined as regular cast members in Season 9.
When a canon closes, its fandom may dissipate as fans move into newer, more active fandoms with open canons. Some fannish friendships survive fannish drift. Others don't.
====Examples of "spinoff fandoms"====
*Highlander's Peter Wingfield: Queen of Swords
*LOTR's Elijah Wood: The Faculty
*The Sentinel's Garrett Maggart: Demon Under Glass
*Smallville's Michael Rosenbaum: Sorority Boys
*Stargate Atlantis' Joe Flanigan: First Monday, Thoughtcrimes
*Stargate Atlantis' David Hewlett: Century Hotel 
*Stargate SG-1's Amanda Tapping: Sanctuary
The 6 Degrees of Canada fandom is an example of a loose conglomerate of small fandoms where, after a certain point, it is hard to say which fandom is the "parent" fandom. Although quite a lot of 6 Degrees fans started with Due South and followed Paul Gross and Callum Keith Rennie into spinoff fandoms from that point, obviously there is no particular order as to which 6 Degrees fandoms they may move on to, such as Last Night, Wilby Wonderful, Slings and Arrows, Hard Core Logo or Twitch City.
===Stylistic drift within fandoms===
As fans move from one fandom to another, they bring with them styles, ideas, terminology and tropes from their prior fandoms. For instance, fans of the Janeway/Seven pairing on Star Trek: Voyager had often previously been fans of Xena: Warrior Princess' Xena/Gabrielle pairing, and often used fannish terms from that fandom. 
If a migration occurs in large enough numbers, this can have a huge impact on the base fandom. For example, in SGA, when popslash fans migrated into the fandom during the hiatus, they brought with them a lot of anime tropes and interest in more whimsical stories, which may explain the prevalence of crack!fic in the fandom. Singular tropes by fandom shows where some tropes started their fannish existence.
==Fannish Drift Survey==
A survey titled Fannish Drift Survey ran between August 9, 2020 - August 22, 2020 to gather data surrounding fandom practices and definitions through time. It was split into two identical surveys, one for the age group between years 1943 - 1980 ("Baby Boomers" and "Gen X") and the other for 1981 - 2020 ("Millennials" and "Gen Z"). The 1943-1980 version of the survey ended with 538 responses and the 1981-2020 version ended with 1,475, for a total of 2,013 responses. It succeeded in gathering thousands of respondents of varying age to define seventeen fandom terms across multiple branches of fandom. The results are a wealth of opinions and varying definitions, and its internet/fandom history section has complied hundreds of accounts of things such as Usenet newsgroups and fandom migrations.