Bookstores change, constantly. They change or they die. If a bookstore looks today as it did a week ago, it is already dying; orders are not being filled, books are not coming in, stock is not turning, business is bad. More than any other business I can think of, a bookstore is about what is new or it is nothing. Clothes last longer on the racks than most books do on the shelf: at least the pumpkin hoody has a season to fail, but a book has only the length of its reviews, or the hope of a staff recommendation, a book tour or local interest to save it from returns, remaindering, oblivion. To last beyond that fragile moment, to live further than its launch, a book needs a place, somewhere to land, a category, or even a subcategory, a niche to nestle in and be found. Because most books are made to slot easily into predetermined shelves, it is easy enough to keep them that much longer where they go; romances, be they about vampires, sleuths or Regency dames, go in Romance, police-procedurals or detective fiction or whodunits are all simply Mysteries in a bookstore. Beyond genre is the broad, baggy land of Fiction, without borders, admitting anyone but nowadays with fewer and fewer truly permanent residents. And the general Nonfiction I know some authors may long for as a wide open space in which they may talk of cabbages and kings is now and has always been even less real, unrestricted but also unsalable, a lazily fenced holding-pen for the unclaimed, subject to panics and enthusiasms that, as they pass, can clear the stock in a day. He or she who insists on writing nonfiction as such is defined not only in the negative, but also builds castles on the sand. One's subject is all. One's identity is one's passport to safe harbor. American historians and politicians, whether they write about presidents, revolutions or depressions Great or small, remembered or present day, are all but so much U.S. History. Fannie Farmer and M. F. K. Fisher are made to have more in common than they may have ever had in life by being Cookbooks, or more genteelly or fashionably Food Writing. Biography is any life between covers.
Readers, or customers as we call them in the trade, are not so much creatures of habit as all this would make them seem. There are those who read only within the confines of familiarity, who, having exhausted one author, look only for like. (Bless them for the ease with which they are served.) But most people read as they do anything else, according to the momentary dictates of whim and inclination, influenced by reviews and current issues, dreams of travel and exploration, to know or to be seen to better themselves, for amusement or escape or for purposes of study, renovation, enlightenment or weight loss.
And so a bookstore must be a living thing. Shelves get adjusted to accommodate new stock, sections expand and contract with something like the regularity of breath, floor-plans shift, tables move, displays come and go, signage changes. And everywhere, everywhere there are new categories, or changes made in the old so that a book might be Sociology but also Poverty & Homelessness, and then Economics, depending on the author's degree, the description in a catalogue, the sense of the buyer, the requirements of the shelver working on the sales-floor. Always the idea is to find a place for each book wherein it might most easily be found, from which it will sell, where it will hopefully need to be restocked.
To categorize and subcategories is the natural habit of booksellers, just as reference and cross-reference is the habit of librarians. The aim is the same, the difference is factored in time. So many people, good bookish people, will exclaim enviously at the luck of a bookseller to work with so many books, and they are right, we are lucky and know it. But that which makes us lucky is also something of a curse, because we can not afford to be the critics and conservators we might fancy ourselves unless we are willing to give up our opinions, sacrifice our good taste and our snobberies if and when a sale is to be made without comment, a bad book reordered, a good book returned. Retail allows for very little sentimentality. Time, I repeat, dictates everything a bookstore may do. So to put a book where the author might not have ever imagined it going, to call a thriller a Mystery, or put one author's collection of occasional pieces in Essays, and another author's collection of equally queer writing in Gay Studies, while it may discomfort said author, is done without malice, no insensibility is meant, no failure to consider a writer's preference or self definition is intentionally offered as an insult. Convenience, expedience is all. If, in seeming to limit a writer's audience, a bookseller can find him or her an audience even of one, then from that a wider readership may be made.
There is no, or ought not to be any, shame in being labeled with modifiers that are not meant to define so much as to locate, to reference only in the hope of being found. If a writer, particularly of nonfiction, is adamant, or in any position to be so, then the publisher may insist that any given book be called ___ and shelved only as ___, and I wish all such authors good luck. We in the bookstores will do our best to honor the intentions of our betters. But unless and until one talks half an hour with Terry Gross, or makes the front page of The New York Times Book Review, the categories and subcategories, and sub-subcategories that bookstores use may be if not the best, then perhaps the only way anyone other than one's mother will find one's book on the social history of German beer (Wine & Spirits/Beer & Brewing,) or the socio-poetics of women's diving (Sports/Olympics) or one's memoir of a summer trekking across an island, while still mourning the loss of a great same-sex love (Travel Narrative or Gay Studies, or most happily, both.)