I'm a book junky. Always have been. If I had a buck for every hour I've logged in a bookstore, I'd be driving a lot nicer car. If I had all the bucks I spent in those stores, I'd be living in a lot bigger house. But fast cars and real estate don't turn me on half as much as imagination and ideas. As I said, a book junky. And to support my habit, I've taken to writing the damn things. Not as blissful a career as I once imagined, but a bit less risky than stealing car stereos, color TVs and VCRs.

My professional work for the last 10 years has also focused on the Internet, so I've paid close attention to how books and computers have intersected. I was an early beta tester for the Library of Congress Subject Headings as that classification system evolved from huge unwieldy tomes to slick little CR-ROMs. The slickest thing about them, to my mind, was the hypertext links they included: from overarching categories like Science to narrower terms like Astronomy, Biology, Chemistry and so on, and how these still-large categories were broken down in turn into increasingly narrower subdivisions. I loved being able to surf that compact taxonomy of all human knowledge, encountering related terms along the way -- pointers to categories I otherwise would never have suspected. Getting a handle on the jargon of an unknown field is a very large part of learning. I was fascinated by how explicit hypertext links could facilitate such learning. I still am.

However, while these categories and their interrelationships illuminate much in themselves, their whole point is to... well, point elsewhere -- in other words, to link to actual works on these subjects. The Library of Congress maps its subject headings to shelf locations. Books in Print, those other big tomes that used to sit behind the counter of most bookstores, maps the same subject headings to -- duh! -- books in print. These have also been turned into CD-ROMs and are now usually hidden away on a PC.

The page doesn't say these are Library of Congress Subject Headings, but trust me, they are. Maybe they don't really reveal all that much about what the book is about -- what the heck is "human ecology" anyway? -- but at least now we know it's not in the same ballpark with The Story of O or Penthouse Uncensored II.

Now suppose after reading it, I like The Spell of the Sensuous a lot and want to find other books like it. I could ask my local bookseller to search those subject headings for similar titles. However, even if I didn't encounter a clerk who had no clue what I was asking for -- subject headings? wha...? -- I'd likely get back a fairly long list of equally puzzling titles. Which ones might I find intriguing, useful? Which ones would I be likely to hate? Not a lot to go on there.

Or, I could look up the other authors who blurbed this book: Bill McKibben, James Hillman, Gary Snyder, Theodore Roszak, etc. If I liked the book and they liked it too, maybe I'd like what they wrote as well. We're homing in on the notion of personal recommendations here. Some large online bookstores have automated this with a technology known as collaborative filtering. You've no doubt encountered this sort of thing in the form: "People who bought this book also bought..." followed by a list of titles. Sophisticated algorithms generate these lists by correlating thousands or even millions of purchases and finding potentially significant groupings. Essentially, the software is uncovering genuine knowledge contributed to the site by the human beings who bought from it.

As promising as this technology may be, two problems immediately arise. First, the software is not only sophisticated, it's expensive. Second, marketers can't resist the urge to "improve" the results, thus often destroying any real utility that might have been delivered. I once encountered a recommendation that alerted me to the "fact" that people who liked Hunter S. Thompson also seemed to buy a lot of Harry Potter books. Me, I'm partial to both, but then I'm a little weird. Let's just say I could feel the invisible hand of bestseller marketing tweaking the collaborative filtering rules behind the scenes -- and not very helpfully.

Independent web bookstores aren't usually awash in spare cash they can blow on advanced software. Also, if they're smart, they're not trying to compete head-to-head on Oprah picks and New York Times bestsellers with 800-pound gorillas like Amazon and Barnes & Noble. What then can the Indies do to carve out viable online market niches? For one thing, they can specialize. For another (intimately related), they can leverage the new breed of *social* networks that the Internet has spawned in such profusion. Time for another story...

For a new book I'm working on (i.e., alternately praying to arcane gods, cursing, and slamming my head against the wall), I recently compiled a list of books and movies that dealt in some way with artificial intelligence, robotics or genetic engineering. My interest here is in pop-culture perception, not academic erudition, so the list was heavy on films and the books that had influenced or inspired them. At first, I thought this would be a piece of cake, but I ended up spending several days on this "little" project. It took me a while to realize that Mary Shelley's Frankenstein (1818) clearly belonged on the same list with "The Terminator" (1984) and "The 6th Day" (2000). (Why Arnold Schwarzenegger stars in so many of these flicks remains a minor mystery; send email if you know.)

I sent my initial list to a handful of online pals, asking if they could suggest additions. Naively, I thought I'd included most of the obvious candidates. Shows just how wrong you can be. A few email replies later, my list had nearly doubled. Some books and films I'd simply overlooked. Others I missed because I wasn't familiar (or familiar enough) with them. Even this small informal example demonstrates the power of social networking. Being online is important, yes, but sharing common interests is where the real power lies. Like-minded contacts quickly amplify relevant knowledge.

Let's backtrack for a second. If I walk into a bookstore and it has one big Science section arranged by author's last name, I'm confronted with titles on everything from bacteriology to quantum mechanics, all in a jumble. If the shelves are further subdivided into Biology, Chemistry, Physics, and so on, I'm a little better off. But still, I'm wishing I had a little more help here, especially if science is not an area I'm deeply versed in (it's not). True, I could ask a clerk, but past experience hasn't left me hopeful on this score. I once inquired about books by William Faulkner at a big chain store. "Is that Western fiction?" the clerk asked? She didn't mean like Western Civilization. She meant like Zane Gray and Louis L'Amour. Minimum wage is a terrible thing to waste.

When bookstores first came online, they replicated the same old paper catalog and shelf arrangement schemes typical of offline marketing and brick-and-mortar store layout. Browse by subject, sure. And maybe by a half dozen subcategories. And then... a deluge of undifferentiable book titles. "Page one of 50. Click here to continue."

That doesn't do me any good. Nor am I usually interested (beyond a certain morbid curiousty) in Top-40 lists. When I go searching books online, which is often, I am nearly always looking for something beyond the bestsellers. I return to book sites that offer the possibility of finding books I don't yet know about. And to find them, I want to hook up with people who share my interests. If an online bookshop can connect me with other readers who can tell me why they enjoyed or hated book X, then just like Arnold: I'll be back.

Christopher Locke (clocke@panix.com) is co-author of The Cluetrain Manifesto: The End of Business as Usual, which went to #4 on the Business Week bestseller list. He is also the author of Gonzo Marketing: Winning Through Worst Practices, named one of the top-10 business books of 2001 by Harvard Business Review, and The Bombast Transcripts: Rants & Screeds of RageBoy, rated R for language, partial nudity and bad attitude.

Further reading:

Carl Hiaasen -- more ticklish torrid tales from Florida
Luis Rodriguez -- starting his own bookshop!
Lawrence Schimel -- if an author writes a book, will a reader ever find it?
Brad Barkley -- another funny guy