Now at some of the larger anime conventions (Otakon held in Baltimore, for example) the attendees don't dress exclusively as anime characters anymore and the Con is flavored by whatever's "hot" at the time regardless of its nation of origin. At the 2008 convention (right after The Dark Knight was released) "Why is everyone The Joker?" At an anime convention.
The Suzumiya Haruhi light novel fandom got a doubling or tripling in size as soon as the anime came out. It would only increase after the dub of the series was announced.
Most mangas get this once they are turned into anime; Soul Eater, for instance. After said anime are dubbed, this happens again, as in the Suzumiya Haruhi example above.
Neon Genesis Evangelion after every major re-release. The English dub VHS tapes were released from 1996-1997, and bootlegs were available since it began in 1995. Popularity tapered off a bit in the early 2000's. The first big Newbie Boom was centered on the DVD releases, of the as-yet unreleased finale movie The End of Evangelion in 2002, and then in 2004 the release of the box set of the Director's Cut episodes. Just as the first Noobie Boom from 2002-2004 was wearing off, the series was aired on [adult swim] from 2005 to 2007, sparking another larger boom because it was airing on basic cable TV. Then another, huge boom came after the Rebuild of Evangelion films started coming out, starting in late 2007 in Japan. Delayed somewhat due to bidding wars over the license, the real boom hit when the English region DVD was released in late 2009.
Happened in-universe in One Piece when Gold Roger was executed and said his treasure would be for the one who found it in the Grand Line. This was know as the start of The Golden Age of Piracy for all the new pirates who embarked in finding it; more senior pirates, however, saw it as a very negative thing as the seas will be plagued by new romance-driven pirates.
Another one occurred after the Whitebeard War, thanks in part to Whitebeard himself. The main goal of the Marines in this war was to snuff out the Golden Age of Piracy. However, Whitebeard, with his dying breath, proclaimed that One Piece does exist, reigniting the idea once again and starting a new era of piracy, as a final middle finger to the World Government and the Marines for the death of Ace, having essentially made the entire war and all the sacrifices the Marines made absolutely meaningless with those last words.
Pretty Cure pre-Heartcatch: a small, happy fandom struggling to get subs and shake off the "yuri fanboy" label. Post-Heartcatch: WHERE DID ALL THESE PEOPLE COME FROM. The reason for the boom is twofold: Heartcatch was the second series of a new era of Precure seasons after Fresh Pretty Cure! changed many of the Classic/Pre-Fresh era's conventions, and Heartcatch also attracted a bigger, more prolific fansub group, bringing the English-speaking fandom same-week or even same-day fansubs for the first time.
The Wandering Son was considered a Cult Classic manga for a while with a pretty small fandom. After the anime came out it didn't increase too much but it still gained a lot more notability within anime communities.
Expect a fandom to get a sudden increase in fans when it's either dubbed by a company or it airs on Toonami.
As with the video games, the Pokémon anime decreased in popularity after the fad days ended. Even around late Johto that was setting in. The Sinnoh arc was when a sudden boom in the fandom came about.
Somewhere around the mid 2000s to the Diamond and Pearl days Pokémon Special went from being a rather obscure adaptation of Pokemon to being well-known. It's pretty much the second adaptation, never mind there are many other manga out there (one's even more long-running).
With the announcement of the Watchmen film, the fan community swelled to massive size as people swarmed to read the original graphic novel and became enraptured. This fandom has increased even more so today, due to the film's release.
After a flurry of early advertising publicity stills for the Guardians of the Galaxy movie were released in 2013 picturing Rocket Raccoon, there was a sudden hubbub about how cool it was that a talking raccoon with a ray gun would be one of the stars of a science fiction story. Those people who'd been fans of the character since his first appearance in 1975 quietly rolled their eyes and continued waiting for the movie.
Wonder Woman is in no way an obscure character but she's always been in the shadow of characters like Batman, Superman, and sometimes even Green Lantern. She's always the main female amongst mainstream comic book characters, especially DC. In The Seventies she was quite popular, even having a very popular show, but for over a decade afterwards she wasn't really doing anything for people outside the comic book fandom. The DCAU in general, especially Justice League, really made people care about Diana again and created a lot of fans for her.
A rare Word of God example: Dan Aykroyd has said that Ghostbusters will always last because young children will always come to find it at the stage when they start to become fascinated by the idea of the afterlife, and what happens after we die. Apparently he thinks people should tell children that when they die, if they step out of line, they spend it in a shoe box.
Gojira was a fairly well-received film in its home country of Japan, but it was the Americanized edit, Godzilla: King of the Monsters, that helped turn Godzilla into a household name across the world.
King Kong vs. Godzilla became the highest-grossing Godzilla movie for decades thanks to the inclusion of the then more famous King Kong as his opponent. The success of the film is also what convinced Toho to turn Godzilla into a franchise of almost yearly films.
The very effective trailers for Godzilla (2014) managed to bring many more people into the Godzilla fandom before the movie itself even came out. Gareth Edwards has frequently noted that it has also brought people back into the fandom from having previously been "closet fans" before; he has been pleasantly surprised by all the unexpected people hearing about what project he is doing and telling him something along the lines of "I like Godzilla. Don't fuck it up."
As with many other fandoms, the movies coming out also led to this.
Ortega y Gasset claimed this happening to Real Life Europe in his (non-fiction) work The Revolt of the Masses. Until ~1800, Europe's population grew slowly to 180 million people; from 1800 to 1914, to whopping 460 millions. Being a cultural pessimist, he blamed the decay of culture on this.
Hannibal Lecter didn't become an icon until the film of The Silence of the Lambs came out nearly a decade after Thomas Harris first created the character.
The Hunger Games. Many people noted that, in the run-up to the film's release, sales of the book were surging as people raced to see what all the hype was about.
The first Twilight book was published in 2005. The initial series were bestsellers but it wasn't until the movie was made a few years later it became a cultural phenomenon.
Infamously, a large number of original series Star Trek fans didn't watch it when it originally aired in the late 1960s. However, Paramount aired reruns of the series in syndication throughout the '70s, which is how a far larger number of people were exposed to it. This wasn't as much of a datable "boom" so much as steady growth across a decade. The success of the '80s-era Star Trek movies exponentially increased the number of Trek fans and led not to a remake, but to a sequel series, Star Trek: The Next Generation. It, in turn, exponentially increased the Trek fanbase even further.
Perhaps an even better example is the 2009 Star Trek reboot film, which was popular even among non Trek fans.
Doctor Who got this in 2005, with the launch of the new series.
And although the show has had a cult profile in the US since the 1970s, since about 2008 the show's profile in the US has been on an upward curve. The fact it's one of the few explicitly SF series airing on American TV in 2010-2011 that's actually surviving and not being cancelled after a dozen episodes (or in danger of cancellation), and with there being no Star Trek-like alternative, has also attracted increased US attention.
The comment above regarding newbies being drawn in by the revival only to find the older series not to their liking is also holding true with new Doctor Who fans, some of whom are finding the 1963-89 series is an acquired taste. This has led to a few schisms between aspects of fandom, such as those who declare Christopher Eccleston, David Tennant or Matt Smith the best Doctor ever, without having ever seen a Tom Baker or Jon Pertwee story in order to develop an informed opinion. Also look at any entry for Doctor Who on this very wiki which only look at the show from the revival's perspective with no knowledge of the first three decades of the show whatsoever. Let's just say it does result in a Double Take from an old series fan to see the Doctor touted as an example on romance and sex tropes as if that had always been the case.
Any song covered on Glee, with the exception of the ones it ripped from the Top 100.
Supernatural got an odd amount of this after Castiel was introduced in Season 4, and some people heard so much about him that they decided to check out the show and got hooked. This being Supernatural, there was wank from the fans who'd started watching earlier.
Band of Brothers had a bit of this after James McAvoy and Michael Fassbender got popular (they were both in it early in their careers), but the majority of the fandom doesn't seem to mind.
The general public only now became aware Syfy Channel makes C-movies with ridiculous titles after comments about 2013's Sharknado suddenly exploded on Twitter.
People who became fans of Marilyn Manson when the cover of "Sweet Dreams (Are Made of This)" got heavy rotation on MTV were a great irritation to fans who had been following the group for several years before that song/video was released. They were known to old-school fans as "Sweet Dreamers," and Manson himself would often follow up live performances of the song with "All you kids can go home now."
The Swedish group The Cardigans had the same problem after their song "Lovefool" was featured on the soundtrack to Romeo + Juliet. It brought them a lot of new fans, but since "Lovefool" was fairly atypical of their normal sound, many of those new fans ended up confused or disappointed.
Red Hot Chili Peppers seem to gain a whole new set of fans with every album, which often leads to them joining forums and annoying everyone with stupid comments. Their most recent "I'm With You" actually lost fans who only liked them for John Frusciante, which made the fandom somewhat happy.
The first was around 1998 (when hide's funeral hitting major worldwide media outlets brought a little interest) to around 2000ish, when MP3 trading first brought them to the awareness of a wide amount of people who weren't Japanese or devoted fans of Japanese metal. This was also the first major Chinese and Thai newbie boom, as this was around when Chinese and Thai underground DJs began to play them.
The second (and first major Western) boom, on the other hand, came around 2005-07, with the debut of YouTube and the title song for Saw IV, IV. Their Performance Video and lives were some of the first jrock uploaded to Youtube, and many Western fans first arrived either with seeing them or hide solo then them on Youtube, and the new song and promised reunion inspired some interest from existing Visual Kei/jrock fans.
The third, smaller one came in 2010 with their playing Lollapalooza, which actually drew Western metal fans and, had the band not petered out for the most part after 2011 with not much activity and constant delays and rumors of breakup (which don't do much to sustain active fandom), might have been their major comeback.
The polarizing practice of sampling tends to result in this. Like with Guitar Hero, it's not a bad thing if gives the newbies exposure to classic songs they otherwise would probably never hear. If said newbies disrespect the original stuff in front of its dedicated fans, however, they're liable to lose a kidney.
The Grateful Dead experienced a surge in fans after their New Wave-influenced single "Touch of Grey" became a Top 10 hit in the United States in 1987. The Deadhead community disparagingly call those who became fans of the band in the late 80's and early 90's as "Touch Heads".
Genesis experienced a newbie boom among their followers in 1986 after the release of Invisible Touch. Both eventually saved the band from falling into oblivion, but displeased the older fans who still mourned the departure of Peter Gabriel and their steady Genre Shiftfrom prog rock to pop music.
The same can be said for Yes, following 1983's very successful 90125, with a (slightly) changed lineup and more New Wave-influenced and pop-friendly songs like "Owner Of A Lonely Heart" topping the charts. Fans of the more progressive Yes call themselves "Troopers" (after "Starship Trooper") and the newbies "Generators" (after 90125's followup, Big Generator.)
Queensr˙che experienced this after the release of the hit single "Silent Lucidity" off the album Empire in 1990. It became a "crossover" hit, so to speak, into the pop-music genre. When the band toured, they realized during at least one show in New York State, that many of the attendees were there solely for that one song, and had no idea about the concept of the rest of the album- or the band's music otherwise. They stopped the concert long enough to explain who the characters were and the basic plot.
Any film or TV show that plays a song that catches on with the masses usually has said masses searching all over the internet for the song itself.
David Bowie had a huge one after he released the mainstream pop-rock album Let's Dance in 1983, but this led into a Dork Age when he tried to appeal more to the newbies than to himself with his next two albums. Fans and critics who'd followed him in The Seventies weren't too happy with him for "selling out", and he became frustrated that newbies didn't understand his not-so-mainstream tendencies, which almost resulted in Artist Disillusionment after the 1987 Glass Spider Tour.
Two songs used in Borderlands became hugely popular after people first heard them in the game. Cage The Elephant's Ain't No Rest for the Wicked and DJ Champion's No Heaven were searched heavily on YouTube after Borderlands was released and there were lots of posted comments stating they searched for the songs because they heard it in the game.
Industrial metal band Combichrist got a bit of a newbie boom when their music was one half of the main soundtrack to the the (controversial) 2013 Devil May Cry reboot, DmC: Devil May Cry (consisting of both already existing tracks like "Never Surrender," and new tracks made for the game like "No Redemption"). It probably helps that the soundtrack was one of the very few areas that even people who complained They Changed It, Now It Sucks didn't have many complaints about (since past games also featured heavy metal soundtracks).
This tends to happen in Warhammer 40,000 when an army gets a new Codex after a long wait, leading to some frustration as people who suffered through years of losing with unplayable armies are accused of being munchkins who jumped on the bandwagon of the latest army right when their force finally becomes competitive.
The release of Dawn of War, which was well-received by both game critics and the 40K fanbase, also gave the tabletop scene an injection of popularity.
Morrowind had this effect on The Elder Scrolls series. In the mid to late 90s, the series was another drop in the staggering bucket of role playing games available for the PC. Then Morrowind was released on both PC and Xbox, bringing the series into the mainstream. After Oblivion and Skyrim's runaway success, the series' status as one of the pillars of western role playing games was cemented.
On renai game forums around the time when several originally-in-English dating sims were popular on Newgrounds, there was constant conflict between the few people who had imported and learned to read untranslated games, and the many people who were wondering why so few Safe For Work games were in English (especially if they were looking for otome games).
In mid-2010, a Fan Translation of Tokimeki Memorial Girl's Side DS was quietly released. Just a month or two later, it was fascinating to notice how a discussion thread on gbatemp.net about plans for a fan translation of the second Tokimeki Memorial Girl's Side received many more replies, and quite a bit more enthusiasm.
Marathon is affected every time a Halo game or a Bungie game is released. It still receives popularity from Halo players because Halo was a spiritual successor to Marathon.
Team Fortress 2 got this every two months or so during the time it was a paid game. Each time a new class pack hit, there'd usually be a TF2 free weekend,so you'd see a lot of newbies on the weekend and more people in the weeks afterwards who bought the game because of the free weekend. Even when there were no free weekends, the people who came back to TF2 just to test out the new weapons swelled server populations immensely.
This predictably pales in comparison to what happened when it went Free To Play. All the usual elements, be it fanbase multiplication, server collapses and withering scorn for the newbies who never payed for it, all got taken even further than usual, and the bitter divide caused by the angry veterans who felt the f2p newbies ruined their game forever, the other veterans who don't feel like it's a huge deal, and the aforementioned newbies that keep coming as the rest get more experience is still felt to this day.
Similar case for Left 4 Dead, which had a similar free weekend a few times. Many players who had the game for a while complained about the wave of new players flooding in and ruining their fun. They also complained about the same thing whenever Valve announced they would sell the game for at least half-off the original price for a weekend.
This happens with a lot of games sold over Steam, for that matter, between both free weekends and almost everything on the catalog going on sale for 50% to 75% off or more for various holiday sales.
Happens regularly with Nintendo games, especially those that went on generation-long hiatuses. You'd be hard pressed to find a person under 13 aware that the Metroid series existed before Primenote which also resulted in many unaware newbies bashing it for "stealing" ideas from Halo, when in fact most of the "stolen" ideas had a basis in canon as far back as Metroid II, a decade before either Halo or Metroid Prime came out. This sometimes gets so bad that people refer to Metroid Prime 2 as simply "Metroid II," which is a completely different game. And for a while, Metroid: Other M was occasionally referred to as Metroid Prime: Other M.
Metroid went through another boom when Super Metroid went on sale for $0.30 on the Wii UVirtual Console. It became one of the best-selling downloadable games on the console, and newbies being a huge portion of the buyers is evidenced by the infamous plethora of Miiverse posts by people unable to figure out how to use the Morph Ball.
Apparently, a lot of people think that the Final Fantasy series started with VII, because for many people, it was the first Final Fantasy game, if not the first RPG, they ever played. This is in part to the series not being released in Europe until this point.
Interestingly, the Final Fantasy VII movie, Final Fantasy VII: Advent Children, also caused this for exposing a new generation who may have been too young when VII came out. Notably, the film was released at the height of the anime boom of the early 2000s which drew many non-Final Fantasy fans to it. It's not uncommon to meet younger Final Fantasy fans who saw the movie before they played the games.
On GameFAQs, this happens during the Christmas season or near it when a big game is released and all the new players flood the boards asking things that many of the new experienced players already know about and expect everyone else to.
Such a boom happened in the Sonic the Hedgehog fanbase during the early 2000's. During the early-to-mid nineties Sonic had been an icon and probably more recognizable among children than Mickey Mouse. But by the late nineties, Sonic had sort of fallen out of style. Then along came Sonic Adventure 2: Battle, Sonic Heroes and Sonic X, all of which helped draw in huge amounts of new fans. The Newbie Boom of Sonic in the early 2000s can largely be attributed to the series going multiplatform after SEGA retired from the hardware industry. With SEGA porting Sonic Adventure 1 and 2 to the GameCube it allowed Nintendo fans to check out what put their once-rival on the map in the first place. This, in addition to the fact that every Sonic game from Sonic Heroes onward was available for every major console allowed the franchise to reach a wider audience. These days it's not uncommon for many Sonic fans under the age of 20 to have started with the GameCube ports of the Sonic Adventure titles, as opposed to the Genesis originals.
World of Warcraft vs. the original RTS series. While the original wasn't exactly obscure among gamers, it was nowhere near the WOW phenomenon - a recurring joke among the WOW fandom is to assume references to Warcraft III mean a third WOW and joke that they haven't even heard of a second WOW.
Blizzard themselves made a joke about this for 2013's April Fools' Day, claiming that they were making a prequel to World of Warcraft that was TBA for 2014, followed by screenshots of Warcraft III.
With the release of Street Fighter IV a wave of new users swarmed the SRK site's forum. Pages of posts containing simple questions and naive arguments started with veterans of the series created a big split between spiteful older members and new posters. "09er" was a unkind term born out of the join date immediately visible on every member's post. It became a pretty hostile environment and seemed difficult to discuss the game as a new player. 'Newbie questions' were limited to a couple threads on the main SF 4 discussion forum which did little to stop the problem because the character forums were far more popular. As a result, the updated forum has a clearly visible section for discussion of the basics of the game and the join date of members is in their profile rather than displayed on every post.
The success of this generation (Xbox 360, PS3 and Wii), in particular the Wii, has lead to many an ignorant newbie who haven't heard of anything beyond Halo or Call of Duty or whatever is on TV at the moment.
The success of the Wii is the most notable, as it was designed to create a Newbie Boom in the first place. It might have worked a little too well, however. It seems Nintendo is having a hard time getting the Wii U to sell to its newfound audience because they don't seem to get how a console cycle works and don't see the Wii U as a new console that's meant to replace the Wii eventually, but rather, as just its gamepad which they believe is an add-on for their Wii.
The Dwarf Fortress community had to batten down the hatches in anticipation of one of these when its creators were interviewed by the New York Times. Another boom occurred when Penny Arcade discussed it in The Rant.
Similar to the GameFAQs example above, fans of nearly any multiplayer game that is released from September to November complain or rejoice in the "Christmas Noob Rush," where a huge volume of new players flood the game for easy kills.
The DayZ mod for ARMA II was given coverage by Rooster Teeth, resulting in what was once a semi-popular mod among the existing ARMA fanbase becoming a phenomenon loaded with clueless newbies who have no clue just what they're getting into with a realistic zombie survival simulator, to the point where more than one person bought the game just for the mod - even the Steam pages for ARMA II and the Operation Arrowhead expansion specifically mention that both are required for DayZ.
With the release of some info on the then-upcoming Postal 3 around 2009, the previous game in the series, for a time, went from "incredibly obscure" to just "slightly obscure". Nobody had still actually played it, of course, but everybody was constantly quoting its protagonist as though they had.
The same effect happened again after Postal 3 actually came out and turned out to be an Executive Meddling-induced trainwreck - Running With Scissors managed to get the original games released over Steam's Greenlight service to distance themselves from "Russian Postal", meaning all the aforementioned non-playing fans of the series now had the chance to actually play it.
MechWarrior Online is doing this for the BattleTech/MechWarrior fandoms, especially in the Classic BattleTech era, which is when MWO takes place. What used to be a relatively small, otherwise generally unified community has, ironically enough, blossomed into a fractious, contentious collection of groups all backing one faction or ideal against others.
PAYDAY: The Heist had a significant rise in the player base when Overkill released the No Mercy DLC, which was a map that took place in same No Mercy hospital from Valve's Left 4 Dead.
The Super Smash Bros. series also had a similar effect when it starred characters from obscure or unknown titles. Earthbound became insanely popular after Ness appeared in Super Smash Bros. while Marth and Roy had fans generate a huge interest in Fire Emblem after the duo appeared in Super Smash Bros. Melee. In Fire Emblem's case, the interest was so high that Nintendo actually localized the 7th game and the series became a huge hit overseas since then (before that point, the series was sold in Japan only). The Ice Climbers from the Ice Climber game got more attention when said climbers appeared in Melee as well. Pit from the Kid Icarus games also got more attention after he appeared in Super Smash Bros. Brawl, and his sudden popularity had Kid Icarus: Uprising produced a few years later. Needless to say, the Smash Bros. franchise made several unknowns into super stars.
Super Smash Bros was very successful in sales, but it wasn't until the Melee incarnation that the series really got popular. Many people that started with Super Smash Bros Melee were surprised to see there was a game before it.
Left 4 Dead was popular, but Left 4 Dead 2 became even more popular and was the first game for many newcomers to play. When The Passing DLC was released, people who never played the first Left 4 Dead wondered who the other survivors were (Zoey, Francis, and Louis), until an update ported all of the first game's campaigns to the second.
OFF used to have an infimal fanbase, merely a fraction of an already tiny RPG-Maker fandom. Cue a workorthree going on hiatus/season break, leaving a huge chunk of Tumblr with nothing to do...
Mario first became a household name with Super Mario Bros. 1, making what had been a series of moderately popular arcade and NES games into a worldwide sensation. While the original Donkey Kong and Mario Bros. still enjoyed a healthy level of notoriety, Donkey Kong Jr. is somewhat more obscure, while Donkey Kong 3 and Wrecking Crew are practically unknown even among Nintendo fans.
And in the Mario Kart series, Mario Kart DS, with its easy-to-use online play, allowed the franchise to explode into the top seller it is now. Previously, Mario Kart fandoms were mostly restricted to competing with each other over long distances via Time Trials (setting the best 1- and 3-lap records) and, with Mario Kart: Double Dash!!, LAN events. This influx of newcomers from Mario Kart DS and onwards got so intense that these veteran communities dissolved and eventually disappeared. Some DID cry "It's Popular, Now It Sucks," but for the most part, the new fans and old fans found common ground in online racing.
Harvest Moon gets this every once and a while. For the longest time most fans came into the series with A Wonderful Life, Friends Of Mineral Town, or their Distaff Counterpart's. Nowadays you're pretty likely to see people who entered the fandom through Tree of Tranquility or Animal Parade.
To say Pokémon was popular in the late 90s would be an extreme understatement but by Pokémon Ruby and Sapphire a lot of the fanbase had moved along and the series wasn't quite as popular as before. Long after the fad days had ended, Pokémon Diamond and Pearl came along and got both old fans and new into the series. In general the DS games (DPPT, Heart Gold/Soul Silver, and the Black/White) games are seen as bringing a lot of people into the fandom. Similarly, the competitive sub-fandom faced a Newbie Boom with X/Y due to the system being less prohibitive, with IV-breeding and hidden abilities being easier to access now.
In its alpha days, before becoming the household name it is today, Minecraft experienced a huge boom when it was the focus of several Penny Arcade strips, a bit before the time of the Nether update. The influx of new people was enough to knock Mojang's web servers off their metaphorical feet, and for a while the Minecraft homepage was a blank white page with a few lines of text.
Trouble In Terrorist Town had this from the Colbert Bump of Seananners and others playing the game. Since most of the players introduced in the game in this fashion play it badly (such as killing people as an innocent for no reason), this is not a good thing for the game's community.
Anarchy Reigns had a minor bump recently on the Xbox360 side when there was a SEGA sale on the Xbox Live Market. The community had been practically dead for a while, but after the sale many more newbies joined, and full 16 players battle royals were held for the first time in months. This boom may be short lived though, as the newbies get easily thrashed by the veterans online.
The introduction of Homestuck's trolls, a boon for shippers and roleplayers of all kinds, has caused an influx of readers who are interested mostly in that one part of the comic (much to the chagrin of many older fans).
This isn't the first time this has happened to 4chan. In 2006, 4chan got e-famous for spam raids of Habbo Hotel, Ebaumsworld and other sites which led to a massive influx of new users. Guess what the response of the users who had been there since 2003-2005 was?
To give yourself an idea: post-2005 users are called "THE CANCER THAT IS KILLING /b/" (in all caps).
Encyclopedia Dramatica may be to blame here.
Every summer, /b/ sees a bit of extra traffic due to school being out. This is referred to by the /b/tards as "Newfag Summer". Naturally, "summerfags" are hardly welcomed.
The creation of the TV Tropes page for Survival of the Fittest, followed by an attempt to get it to Trope Overdosed, caused a flood of new members to join the site from TV Tropes. While this was initially met with some displeasure, it could be argued that the newbie flood saved it from dying out, as the site had begun to flag in the middle of version three.
The Web itself drew a lot of people to the Internet, much to the annoyance of people who were regulars on Usenet and Gopher. See Eternal September.
This happened to the My Little Pony fandom when My Little Pony: Friendship Is Magic started to air. Previously, the fandom was a haven for mostly females (not that male fans didn't exist though) who loved the toys and fondly remembered the G1 cartoons. Then when Friendship is Magic was introduced, the previous fandom was swamped by a huge influx of new, mostly male fans (dubbed "bronies"). Similarly, the brony fandom itself experienced a boom around Season 2, when the initial shock of "boys liking girl things" wore off for the most part and people began to check it out for the sake of the show itself.
Time Squad was a 2001 Cartoon Network show about time police that had a decent fan following and was nominated for five Annie Awards. In the summer of 2012, the Tumblr tag for the show exploded, with dozens of fans coming out of the woodwork and a sizable amount of fanart and fanfiction resulting.
Family Guy had a song by The Trashmen called Surfin' Bird play out in the episode "I Dream of Jesus" where Peter gets obsessed over the song. This caused fans of the show who never heard of the song before going on YouTube to find the song and commenting they wanted to find the song because of Family Guy.
The New Teen Titans was quite well-known in The Eighties amongst comic book fans but is generally unknown outside of comic book fans. With the Teen Titans cartoon not only did the series in-general get more popular but so did many of the characters.
Daria ran from 1997 just into 2002, but didn't get a DVD release until 2010 because of licensing issues. Many of the buyers were people who had been a bit too young for the show when it first aired, adding many teenagers and 20-somethings to the fandom.
During the 18th century, many new agricultural practices were invented and spread from Britain throughout the rest of Europe. Leading to a population boom, and after the new people came of age, to great changes in society - cottage industries in Britain, preparing the Industrial Revolution, and the very French Revolution on the continent.
Every school sees this each Fall, from kindergarten to postgraduate. Not coincidentally, this is when any and all internet communities see a spate of new names piping in, and sometimes settling in.