I was in a bookstore today, looking through the travel writing section and fuming at the way the books were organized. I've read a few books recently about Germany and Switzerland, and I was looking for more in this vein, but the shelves were laid out alphabetically by author, rather than by region or country. The upshot is, I scanned the entire set of shelves and came up with absolutely nothing. Which is probably for the best, because I shouldn't be adding to my book collection (just the opposite), but it got me thinking about how people browse.
The way the publishing business is going, bookstores would probably prefer that you go straight to the name authors, buy a book (or several), and go. But one of the great advantages bookstores have traditionally had over Amazon is in the browsing - where you go with a vague idea of what you want, you look through the shelves, find it, but then hang on, this looks interesting - oh, and I'd better pick this one up, too...
I know that Amazon offers suggestions for similar books, but the two books I searched for online just now - Germania by Simon Winder and Swiss Watching by Diccon Bewes - only pulled up results with the exact same subject matter (and incidentally, books I already own). When I tried adding other criteria, namely travel writing and European history, I promptly found myself staring at a list of Fifty Shades of Grey books and copycats.
So Amazon's algorithm isn't quite flawless, and it's possible what I'm looking for doesn't exist. But this also proves how important it is for bookstores to shelve their stock intelligently - you'd be pretty disappointed if you ventured into the history section at your local Barnes & Noble or Waterstone's and found poorly written erotic fiction all over the place.
Of course, matters aren't helped by established authors suggesting that different genres should be shelved together. Their thinking is that by placing science fiction and fantasy on a different shelf (typically at the back of the store, well away from sunlight), you reinforce the stereotype that only pasty virgins read that stuff. The solution, therefore, is to just stock all fiction together, so that folks who don't normally read in that genre can be enticed over to the dark side. George RR Martin, I believe, is one proponent of this idea, wistfully recalling his youthful days of perusing spinner racks filled with paperback SF, fantasy, westerns, thrillers, etc.
With all respect to the man who's sold millions of books and been proclaimed the American Tolkien by Time's Lev Grossman, not so fast. Spinner racks aside (I like the idea of those), these supporters of breaking down the genre walls are perhaps forgetting that no matter how visible their own books get, they'll always get shunted off the shelves in favor of the latest claptrap from Ian McEwan or Jonathan Franzen. Think of all the places where you saw reviews or discussions of Freedom, when it came out; now think of all the places where you saw people talking about A Dance with Dragons. Much as we in the genre would like to think otherwise, SF/F isn't really taken all that seriously by Muggles (sorry, couldn't resist).
Personally, though? I don't see this as a problem. Science fiction and fantasy is just as prone to Sturgeon's Law as any other genre, but at least it typically doesn't get writers trying to show off what they learned in their fancy creative writing MFA course.
On a more practical level, the genre ghetto should stand simply to allow new entrants to find more of what they're looking for. If you want to get people to read more SF/F, you put Tad Williams next to Connie Willis, not Irvine Welsh; just like if you want people to read more stuff like Trainspotting, you put it among similar books by similar authors.
So let's keep the science fiction and fantasy clear of the horror books, and the mysteries, and the literary fiction. Not because it's less worthy, but because you don't want to get PD James mixed up with EL James...