Indie publishing is particularly well-suited to genre fiction, where even the most obscure sub-sub-genre can carve out a following (e.g. historical zombie fiction). One new genre or sub-genre I've discovered through the Twittersphere is steampunk. I'm hardly a devotee, but I do confess a grudging fascination.
Movie examples of steampunk are Terry Gilliam's "Brazil" and the movie version of "Wild, Wild West." The hallmark of the genre are clunky 19th-century style machines, often powered by steam, that mimic more modern inventions in a retro, quasi-Victorian setting. "Brazil" I found perplexing at the time -- it seems to depict a future society, but set in an indeterminate past. "Wild,West West" annoyed me because I thought it perverted a TV show I'd always enjoyed. But the campy TV show, which translated James Bond-type gadgetry into the wild west, clearly fits within the steampunk category and the movie just carries that to an extreme.
The Politics & Prose email this week featured a staff pick called Pavane by Keith Roberts, the reissue of a 1968 book billed as a science fiction/alternative history classic. The premise is that Queen Elizabeth I was assassinated in 1588, so that the invasion of the Spanish Armada was successful, allowing the Catholic Church to beat back the Protestant Reformation in England and northern Europe. Over time, in this alternate history, the pope becomes not only the ruling spiritual but also the ruling temporal power in Europe as well as a colony known as Newworld.
No mention of steampunk, but the first of the six interconnected stories forming the book is about a "haulier" who drives a steam locomotive. It took me some time to realize this locomotive and the "waggons" it pulled were not on rails, but road in ruts on the road. The action takes place in Durnovaria, or Dorchester, where they actually do have a Steam Fair featuring these so-called traction engines. OMG, I think, this is steampunk.
But, no, steampunk enthusiasts don't seem to accept Pavane as genuine steampunk (don't ask me why), but at best as "proto-steampunk" or something that steampunk fans will like. Steampunk proper begins only in the 1970s, it seems, so that even Jules Verne is excluded, though obviously an inspiration for the genre.
Be that as it may, we have in Pavane a book that is science fiction, alternate history, proto-steampunk, dystopian, and maybe a few other things. It is also terrifically well written.
Now, typing a book to best exploit the Amazon bestseller algorithms has become a minor art in the indie world, with numerous blogs explaining how your book becomes more prominent if you choose a genre path that's less crowded. I'm not convinced. My most successful KDP Select promotion was when I had checked the very broad categories of historical fiction and thriller. The latest promotion was not nearly so successful after I checked the much narrower category of espionage.
The Grand Mirage is a historical thriller. It is historical fiction, but it will not appeal to all fans of that genre. It is a political thriller, but it won't appeal to all those fans, either. It is an old-fashioned adventure story, but that's not a genre. Next month I will re-issue Gold, which is a financial thriller, a sub-genre that has never been wildly popular. Because it is 20 years old, it actually takes on some aspects of a historical thriller, too.
Genre categorization has always been important. Print books started printing a category on the back cover so that bookstores could shelve it properly, and this was important to people browsing for titles in a certain category. A misshelved book could result in a lot of lost sales, back in the day.
The advantage of indie publishing and internet ebook sales is that it opens the field to all sorts of narrow-interest sub-genres. It will undoubtedly continue to be important to categorize a book so that fans of a particular genre can find it. There's a risk, though, that those books fitting the narrowest definitions will become the most popular, just because they're easy to find. Mirage could appeal to thriller fans who also like history, or to history fans who also like thrillers, but neither may ever find it. Ditto for Gold.