Full disclosure: It was late at night, in a fit of furtive self-Googling, that I discovered the first Amazon customer review of my debut book of fiction. “Superb,” wrote Grady Harp of Los Angeles. “Fascinating … addictive.” Not to mention “profound.” Such extravagance should have aroused suspicion, but I was too busy basking in the glow of a five-star rave to worry about the finer points of Harp’s style. Sure, he’d spelled my name wrong, but hadn’t he also judged me “a sensitive observer of human foibles”? Only when I noticed the “Top 10 Reviewer” tag did I wonder whether Grady Harp was more than just a satisfied customer. After a brief e-mail exchange, my publicist confirmed that she’d solicited Grady Harp’s review.

I suppose I shouldn’t have been surprised, but I had imagined Amazon’s customer reviews as a refuge from the machinations of the publishing industry: “an intelligent and articulate conversation … conducted by a group of disinterested, disembodied spirits,” as James Marcus, a former editor at the company, wrote in his memoir, Amazonia: Five Years at the Epicenter of the Dot.Com Juggernaut. Indeed, with customers unseating salaried employees like Marcus as the company’s leading content producers, Amazon had been hailed as a harbinger of “Web 2.0”—an ideal realm where user-generated consensus trumps the bankrupt pieties of experts. As I explored the murky understory of Amazon’s reviewer rankings, however, I came to see the real Web 2.0 as a tangle of hidden agendas—one in which the disinterested amateur may be an endangered species.

On the surface, Grady Harp seems just the sort of enlightened consumer who might lead us out of Web 1.0’s darkness. A 66-year-old gallerist, retired surgeon, and poet, he has reviewed over 3,500 books, CDs, and movies for Amazon. In turn, he has attained a kind of celebrity: a No. 7 ranking; a prominent profile on the Web site; and, apparently, a following. In the week after his endorsement of my work appeared, more than 100 readers clicked on a button that said, “I found this review helpful.” His stated mission is to remain “ever on the lookout for the new and promising geniuses of tomorrow.” At present, Dr. Harp’s vigil runs to about 500,000 words—a critical corpus to rival Dr. Johnson’s—and his reviews are clearly the product of a single, effusive sensibility. Jose Saramago’s Blindness is “A Searing, Mesmerizing Journey” (five stars); The Queer Men’s Erotic Art Workshop’s Dirty Little Drawings, “A Surprisingly Rich Treasure Trove” (five stars).

Such efforts have led a quorum of enthusiasts to hail Harp as a standard-bearer for literary amateurism. “Keep your pen hot, Grady!” one comments. Yet an equally energetic chorus of detractors carps that Harp’s Amazon reviews are more self-interested than they might appear. The comment threads accompanying Harp postings devolve into litanies of accusation: GH engages in back-scratching; GH is unduly influenced by publishers; GH has failed to read the book under review.

My own research suggests that GH is no more or less credible than Amazon’s other “celebrity reviewers.” Harriet Klausner, No. 1 since the inception of the ranking system in 2000, has averaged 45 book reviews per week over the last five years—a pace that seems hard to credit, even from a professed speed-reader. Reviewer No. 3, Donald Mitchell, ceaselessly promotes “the 400 Year Project,” which his profile identifies only as “a pro bono, noncommercial project to help the world make improvements at 20 times the normal rate.” John “Gunny” Matlock, ranked No. 6 this spring, took a holiday from Amazon, according to Vick Mickunas of the Dayton Daily News, after allegations that 27 different writers had helped generate his reviews.

Absent the institutional standards that govern (however notionally) professional journalists, Web 2.0 stakes its credibility on the transparency of users’ motives and their freedom from top-down interference. Amazon, for example, describes its Top Reviewers as “clear-eyed critics [who] provide their fellow shoppers with helpful, honest, tell-it-like-it-is product information.” But beneath the just-us-folks rhetoric lurks an unresolved tension between transparency and opacity; in this respect, Amazon exemplifies the ambiguities of Web 2.0. The Top 10 List promises interactivity—”How do I become a Top Reviewer?”—yet Amazon guards its rankings algorithms closely. A spokeswoman for the company would explain only that a reviewer’s standing is based on the number of votes labeling a review “helpful,” rather than on the raw number of books reviewed by any one person. The Top Reviewers are those who give “the most trusted feedback,” she told me, echoing the copy on the Web site.

As in any numbers game (tax returns, elections) opacity abets manipulation. Amazon’s rankings establish a formal, public competition for power—or its online equivalent, recognition—wherein each competitor follows his own private sense of fair play. Or not. On the tongue-in-cheek Harriet Klausner Appreciation Society blog, I found allegations that Grady Harp’s 92,000 “helpful votes” are the product of collusion—that Amazon reviewers often strike e-mail bargains to “yes” one another’s reviews. Klausner herself told the New York Times in 2004 of a conspiracy to unseat her. Though Amazon officials assured me that they do their best to “weed out” loyalty votes when calculating the reviewer standings, recent software innovations seem to come down on the side of the weeds. A social-networking feature allows a reviewer to identify hundreds of other reviewers as “friends”; an RSS option lets them track his feedback in real-time. Certainly, Harp has been generous to his Amazon “friends,” among whom are authors he has reviewed and others for whose self-published books he has provided jacket copy. (“A book that is well worth the attention of our weary state in America today.”—Grady Harp, Amazon.com.) The watchdogs of HKAS point to Harp’s staggering vote total—a tally surpassed only by Klausner’s—as evidence that this generosity has been repaid.

Given Amazon’s lack of greater transparency, it’s hard to judge the merits of the vote-swapping claims. What is clear is the corruptibility of democracy, Web 2.0-style. Then again, from a shareholder’s perspective, the fact that anyone cares may indicate the rankings’ success. Qualitative research affirms that “books with more and better reviews sell better,” according to Cornell sociologists Shay David and Dr. Trevor Pinch, co-authors of a 2006 analysis of online recommendation systems. To the extent that competitive energies drive Top Reviewers and their nemeses to generate content, and to spend time on and publicize Amazon.com, the chief beneficiary of misuse of Amazon’s rankings system is Amazon itself.

This is not to say that a Top 10 ranking doesn’t come with some sub rosa incentives for the reviewer. Free books, first and foremost; in an e-mail, Grady Harp told me he was “inundated with books from new writers and from publishers who know I love to read first works.” This fall, when it invited select Top Reviewers to join its Vine program—an initiative, still in beta-testing, to generate content about new and prerelease products—Amazon extended the range of perks. “Vine Voices” like Mitchell and Harp can elect to receive items ranging from electronics to appliances to laundry soap. As long as they keep reviewing the products, Amazon’s suppliers will keep sending them.

However, by refashioning Web 2.0 as a proprietary marketplace, Amazon’s reviewer rankings subject enthusiasts like Grady Harp to the same pressures that confront the professionals they were supposed to replace. To keep writing, lest another reviewer usurp one’s spot. To say something nice, in hopes that someone will say something nice about you. And to read for work, rather than for pleasure. “I have a tall stack of books staring at me,” Harp wrote, in a wistful moment.

“At times this sense of obligation prevents me from having time to read the things I personally want to read—the works of McEwan, Toibin, Crace, White, Bolaño, Sebald …”

Like celebrity bloggers and Wikipedia “Gnomes,” then, the Top Amazon Reviewer heralds the arrival of a curious hybrid: part customer, part employee. This feels like a loss. But perhaps it means that in the coming age, every writer will be a salesman: up past dark, sifting through the data stream for evidence that somewhere, some honest soul is buying.