Older Than Radio: After authors such as Ann Radcliffe and Matthew Lewis popularized Gothic Fiction in the late eighteenth and early nineteenth centuries, hundreds of lesser known Gothic novels and condensed re-writes of better known Gothic novels were published in an attempt to cash in. This largely died down by the 1820s, but the large number of forgotten novels published by Minerva press (which also published Radcliffe's classic, The Mysteries of Udolpho) is a testament to the massive popularity of Gothic novels at the turn of the nineteenth century. Indeed, many of these "trade Gothic" works can be bought from Zittaw Press, Udolpho Press, and Valancourt Books.
The Da Vinci Code remained on best-seller lists for an obscene number of months, resulting in many copycat quest novels. The Da Vinci Code itself follows the pseudohistory/conspiracy book Holy Blood, Holy Grail (1982, republished 1996), merging itwith Brown's usual 'thriller starring male college professor and companion sexpot in an exotic European locale' formula.
That's not to say anything from The Vampire Diaries, a 1991 book series who saw a rebirth with the YA vampire fever, being brought back to readers' knowledge, and spawning a TV series.
Popular romance novel Fifty Shades of Grey was originally a Twilight fanfiction. It was so successful that it spawned its own followers: two novels entitled Gabriel's Inferno and Gabriel's Rapture have gotten a seven-figure deal. And like Fifty Shades, these novels started off as Twilight fanfics. Read about it here.
Speaking of Fifty Shades of Grey, it spawned the Eighty Days trilogy; another trilogy of BDSM romance books called Eighty Days Yellow, Eighty Days Blue and Eighty Days Red. As you may have noticed, even the title is designed to sound a bit like "Fifty Shades." It's no coincidence that it's got a number in the beginning and is followed by a color. And then there's the short story collection 12 Shades of Surrender, which is exactly what it sounds like.
Jasper Fforde pokes fun at this phenomenon in The Well of Lost Plots: A Thursday Next Novel. While Thursday is exploring the Well of Lost Plots, where books and characters are created from scratch, a Mr. Exposition explains to her that, when one character is written with a particularly forceful or distinctive personality, characters-to-be are affected by that and take on those traits. A side-effect of Daphne Du Maurier's Rebecca, for example, is that hundreds of impressionable characters imitated the creepy and possibly psychotic lesbian housekeeper of the story, which results in, for Jurisfiction, an army of Mrs. Danvers clones. At the end, he offers Thursday, "Can I interest you in a wise oldmentor figure?"
While Tom Clancy was not the first guy to do the techno-thriller, he spawned a lot of imitators.
The UK and Ireland have recently seen a surge of popularity for "misery lit" books based on stories (some true, some not) of childhood abuse/Parental Abandonment etc. They all look exactly the same (a mostly white cover with a photo of a big-eyed child and a heartstring-tugging title in twirly, bright lettering), occupy entire shelves in shops, and seem to be competing with each other to see which can be the most depressing. Possibly launched in America by A child called it by Dave Peltzer, which then brought the craze to Britain and Ireland when it was released there. Many bookshops now consider these a legitimate genre and have a section devoted to them, often called "Tragic Lives".
The Kimani Tru series, books about African-American urban teens, now has many imitators.
Almost everybody knows of John Milton's Paradise Lost. What many people don't know is that Dutch writer Joost van den Vondel published De Lucifer, a play with the same basic plot, roughly four years before Milton even started writing his poem. While it's doubtful that Milton knew enough Dutch to fully understand the play, it's no stretch to say that he was inspired by the premise. A shorter, anglo-saxon poem based on the same themes seems to be an actual blueprint of Milton's poem.
R.L. Stine's success with Goosebumps led to dozens of similarly named series being published including Bone Chillers, Deadtime Stories, Shivers, Spinetinglers, Spooksville, and Strange Matter. And Galaxy of Fear is pretty clearly taking inspiration from Goosebumps, though the books follow one set of protagonists for the whole series and have a clear arc. Subject matter is largely the same, the kids are around the same age, there are constant Cliffhangers and Pseudo Crisis chapter endings...
At one point in the mid-nineties you couldn't turn around in a British bookshop without tripping over a "comic fantasy" with a Josh Kirby style cover. All they proved was there is only one Sir Terry Pratchett.
After the success of Don Pendleton's The Executioner books, a flood of copycat vigilante justice series jumped onto the bandwagon, with names like "The Destroyer" (which lasted the longest), "The Butcher", "The Penetrator", "The Liquidator", etc. Oh yeah, and a little comic book by Marvel called The Punisher.
Many of these novels have covers featuring circular emblems reminiscent of the Mockingjay pin. While writers have no control over what the covers look like, these might be publishers' attempt to get the books popular so it still counts as this trope. For example: Divergent's Dauntless symbol, the Legend Trilogy's Republic logo, The Testing's coin or I Am Number Four's Loric number symbols. This has even spread to other genres in YA, such as fantasy: look at The Demon Kings serpent flashpiece, Snow Like Ashes's chakram or the Charter Magic symbols found on the newer editions of the Old Kingdom series.
Cory Doctorow's Little Brother has one: Brain Jack by Brian Falkner, and a few other stories about Deadpan Snarker teen hackers resisting a government technological regime.
While the whole fictional-story-written-as-a-journal/diary is nothing new, Jeff Kinney's Diary of a Wimpy Kid series has at least one major imitator: Rachel Renee Russell's Dork Diaries. Other humorous graphic novel/children's novel hybrid series that have followed in Greg Heffley's wake include Middle School (James Patterson), Tales of a Sixth Grade Muppet, Timmy Failure (Stephan Pastis), and twoStar Wars-inspired series in Origami Yoda and Jedi Academy.
The success of Black Beauty led to the (also successful) novel Beautiful Joe in 1893 (the latter even references the former); both novels helped raise awareness of animal cruelty.
The non-fiction book The World Without Us (2007), whose premise is showing what would happen to the world if all humans suddenly vanished one day, was followed by two 2008 documentaries that were basically The World Without Us with the serial numbers filled off: Life After People and Aftermath: Population Zero (each would later give birth to full TV series, with only Life staying true to the original premise). After that there was a noticeable shift in post-apocalyptic fiction from sterile, gray or brown settings often brought by nuclear warfare to "green" overgrown cities where humans had been decimated by some disease and/or anarchy, but everything else was doing alright: I Am Legend (2007), Revolution (2012), Tokyo Jungle (2012), The Last of Us (2013) and Dawn of the Planet of the Apes (2014).
Dime Novel hero Nick Carter was pretty clearly a source for Doc Savage. Reading through the Nick Carter dime novels is like going through a Doc Savage checklist: trained since childhood by father to be a mental and physical superman, travels the world righting wrongs and battling evil, a master of disguise, has a Rogues Gallery full of sinister villains, leads a team colorful assistants, etc. Its Doc Savage, only in the 19th century.
Additionally, TFIOS seems to have made Young Adult fiction that doesn't fit into the Paranormal Romance or dystopian society tropes a bit more popular; instead, YA romances are trending towards the more mundane.
Things are gonna get complicated now, so listen up. When The Millennium Trilogy was translated to English, the publisher decided to give the books in the series similar-sounding titles. So they translated the title of the second book, The Girl Who Played With Fire, completely faithfully, and then gave the other two books brand-new titles: The Girl With the Dragon Tattoo and The Girl Who Kicked the Hornets' Nest.note The original Swedish titles of the books translate roughly into "Men who hate women" and "The pipe dream that blew up." That way, it was immediately obvious to people that the books were related. A few years later, a Swedish humor novel by Jonas Jonasson was translated into English. Its title was faithfully translated into English as The Hundred-Year-Old Man Who Climbed Out the Window and Disappeared. This title clearly resembled the Millennium titles, and because of this, it's become common for English-language publishers to give Swedish novels English titles along the lines of "The person who did a thing."
Jonas Jonasson's Spiritual Successor to The Hundred-Year-Old Man Who Climbed Out the Window and Disappeared had a Swedish title that translates to The Illiterate Who Could Count. The English translation was named The Girl Who Saved the King of Sweden.
Swedish writer Catharina Ingelman-Sundberg wrote a book called Kaffe med rån, which can mean both "Coffee with wafers" and "Coffee with robbery." The English translators gave it the title The Little Old Lady Who Broke All the Rules, and in another example of this trope, gave its cover the same kind of design as Jonasson's novels. When she wrote a sequel, the English translation was named The Little Old Lady Who Struck Lucky Again!
One formula that has become popular recently in Brazil are literary adaptations of Minecraft campaigns, mainly made by Youtubers such as Authentic Games and RezendeEvil, whose channels are crowded with Minecraft gameplay videos.