Fandom drives the franchise novel. If a dedicated fanbase of ecstatic and hot-blooded readers exists hungry for more product, a corporate-based books series will commission writers to feed them. You only need to again look at Star Trek and Star Wars, a TV show (and later movie series) and movie series (and soon to be TV show) that have complete separate universes for the continuity of a novel series.
I've dabbled in reading franchise novels, both media tie-ins and continuations. At their best they do provide a sort of pulpy enjoyment. I have gone through a few Stars Wars opuses and read some of R. A. Salvatore's "Forgotten Realms" fantasies. I have even suffered through more than one Conan "pastiche" novel, usually in the name of writing reviews so other curious fans of Robert E. Howard know which ones to pick up and which to avoid like a black lotus cloud. Most Conan stories outside of Howard's are sad, but there are some exceptions. I have to tip my hat to my friend John C. Hocking for his work on Conan and the Emerald Lotus, and Karl Edward Wagner's Conan: Road of Kings is also a good show. Some of John Robert Maddox's Conan adventures aren't too shabby, either.
But the popularity of fantasy and science fiction franchise novels brings up an interesting "What if?" question.
"What if J. R. R. Tolkien's Middle-Earth was turned into a continuing book franchise?"
Outside of fanfic, there are no pastiche or continuation novels based on the setting Tolkien developed over his lifetime, the mythic Earth of The Lord of the Rings and The Silmarillon. Although Tolkien's estate has commissioned some stories as "homages" to the good professor's work, they have never permitted nor, I'll wager, ever will permit the publication of new adventures from new authors.
That is exactly how it should be. Tolkien's world is so uniquely his own, so tied in with his entire life, and so complete within the scope of his writings and extensive notes, that letting anything be "officially" added to it is unthinkable. It would ring more hollow than any pastiche work.
But... what would those hollow books be like if they were allowed? You may shudder to think of it, but I decided it would be amusing to imagine the ridiculous ideas that might result.
Placing myself in the mindset of a potential publisher who has hacked out a deal with the Tolkien estate, I've hatched brief book proposals for a never-to-be-seen (thank the Valar!) series, Middle-Earth Adventures. I've written these proposals in the form of promotional blurbs used to excite retailers, and used my own experience with franchise novels to imagine some of the weirdness that might pop up should anyone dare to do this.
The immediate follow-up to The Lord of the Rings... the direct sequel fans have clamored to see for years! Aragorn is now King Elessar, seated on the throne of Gondor, happily wed to Arwen Evenstar. But even though the Dark Lord Sauron has fallen and passed into shadow, evil still rots at the edges of the Kingdom. The Black Númenorean sorcerers who served Sauron faithfully for hundreds of years, slowing their aging through diabolic magics, have gathered together the survivors of Mordor and carved out an alliance with the Corsairs of Umbar the South. Aragorn must lead an army against these survivals of the dark times before his fledgling kingdom is split apart. But can even he escape the trap that Black Númenoreans have set for him, which will feed him to... Shelob? The horrid demon in spider form has licked her wounds and is ready for more dark fantasy action. Also, prepare to meet the new heroes of the age, Aragorn's personally picked citadel guards who take center stage in this thrilling new trilogy.
The Young Sméagol Chronicles
Before the ring dragged him into torment as Gollum, Sméagol was curious fellow who wandered wide over the Anduin river valley, searching out treasures and secrets. This delightful series of juvenile books follows his adventures as he explores the woods and rivers of Middle Earth, makes new friends, and faces terrible dangers such as the rogue eagles of Mirkwood, and Hobbits under the spell of the the tower of Dol Guldur. Fans young and old of The Lord of the Rings will thrill to discovering the gentle soul whom the ring would eventually twist into a tragic figure of the ages.
Tales of the Last Alliance
The end of the Second Age is approaching, and this four-part series of novels shows readers different aspects of the great war between Sauron on one side and Men and Elves on the other. Action and spectacle to rival The Lord of the Rings will accompany the warriors who stand up to the hordes of Mordor. For the first time, readers will experience Sauron himself wielding the One Ring. Isildur and Anarion take the lead roles in the last two novels, and these will certainly be on the "must-read" list of any Tolkien fan.
The Annals of the White Council
The three wizards—Gandalf, Radagast, and Sauruman—with Galadriel, Elrond, and Círdan, form a council ready to wipe out evil in Middle Earth! Against them are the devious minions of Sauron and the Lord of the Nazgûl. Learn for the first time the true identity of the "other two" wizards of the group. This on-going series mixes J. R. R. Tolkien with magical espionage, and will especially appeal to teen readers.
Epics of the Elder Days
The time of The Silmarillion as you've never seen it before. Each novel is a complete, self-contained epic about the Elves and their adventures in Middle Earth in younger days, before the dominance of Men. All-new heroes fight with classic adversaries, and the fresh setting means almost any reader can get into this series, without knowledge of The Silmarillion or even The Lord of the Rings. One book will feature an untold tale of Beren's adventures that fits within the scope of "The Tale of Beren and Luthien."
My head hurts even thinking about how dreadful these could be. These aren't exaggerations for humorous purposes, either—I could see a publisher seriously suggesting each one of these.