Giving raves to family members is no longer acceptable. Neither is writers reviewing other writers. But showering five stars on a book you admittedly have not read is fine.
After several well-publicized cases involving writers buying or manipulating their reviews, Amazon is cracking down. Writers say thousands of reviews have been deleted from the shopping site in recent months.
Amazon has not said how many reviews it has killed, nor has it offered any public explanation. So its sweeping but hazy purge has generated an uproar about what it means to review in an era when everyone is an author and everyone is a reviewer.
Is a review merely a gesture of enthusiasm, or should it be held to a higher standard? Should writers be allowed to pass judgment on peers the way they have always done offline, or are they competitors whose reviews should be banned? Does a groundswell of raves for a big new book mean anything if the author is soliciting the comments?
In a debate percolating on blogs and on Amazon itself, quite a few writers take a permissive view on these issues. The mystery novelist J.A. Konrath, for example, does not see anything wrong with an author indulging in chicanery.
"Customer buys book because of fake review = zero harm," he wrote on his blog.
Some readers differ. An ad hoc group of purists has formed on Amazon to track its most prominent reviewer, Harriet Klausner, who has more than 25,000 reviews. They do not see how she can read so much so fast or why her reviews are overwhelmingly and, they say, misleadingly exaltations.
"Everyone in this group will tell you that we've all been duped into buying books based on her reviews," said Margie Brown, a retired city clerk from Arizona.
Once a populist gimmick, the reviews are vital to making sure a new product is not lost in the digital wilderness. Amazon has refined the reviewing process over the years, giving customers the opportunity to rate reviews and comment on them. It is layer after layer of possible criticism.
"A not-insubstantial chunk of their infrastructure is based on their reviews and all of that depends on having reviews customers can trust," said Edward W. Robertson, a science fiction novelist who has watched the debate closely.
Nowhere are reviews more crucial than with books, an industry in which Amazon captures nearly a third of every dollar spent. It values reviews more than other online booksellers like Apple or Barnes & Noble, featuring them prominently and using them to help decide which books to acquire for its own imprints by its relatively new publishing arm.
So writers have naturally been vying to get more, and better, notices. Several mystery writers, including R.J. Ellory, Stephen Leather and John Locke, have recently confessed to various forms of manipulation under the general category of "sock puppets," or online identities used to deceive. That resulted in a widely circulated petition by a loose coalition of writers under the banner, "No Sock Puppets Here Please," asking people to "vote for book reviews you can trust."
In explaining its purge of reviews, Amazon has told some writers that "we do not allow reviews on behalf of a person or company with a financial interest in the product or a directly competing product. This includes authors."
But writers say that rule is not applied consistently.
In some cases, the ax fell on those with a direct relationship with the author.
"My sister's and best friend's reviews were removed from my books," the author M.E. Franco said in a blog comment. "They happen to be two of my biggest fans."
Another writer, Valerie X. Armstrong, said her son's five-star review of her book, "The Survival of the Fattest," was removed. He immediately tried to put it back "and it wouldn't take," she wrote.
In other cases, though, the relationship was more tenuous.
Michelle Gagnon lost three reviews on her young adult novel "Don't Turn Around." She said she did not know two of the reviewers, while the third was a longtime fan of her work.
"How does Amazon know we know each other?" she said. "That's where I started to get creeped out."
Robertson suggested that Amazon applied a broad brush.
"I believe they caught a lot of shady reviews, but a lot of innocent ones were erased, too," he said. He figures the deleted reviews number in the thousands, or perhaps even 10,000.
The explosion of reviews for "The 4-Hour Chef" by Timothy Ferriss shows how the system has evolved from something spontaneous to a means of marketing and promotion. On Nov. 20, publication day, dozens of highly favorable reviews immediately sprouted. Other reviewers quickly criticized Ferriss, accusing him of buying supporters.
He laughed off those suggestions.
"Not only would I never do that it's unethical I simply don't have to," he wrote in an email, saying he had sent several hundred review copies to fans and potential fans. "Does that stack the deck? Perhaps, but why send the book to someone who would hate it? That doesn't help anyone: not the reader, nor the writer."
As a demonstration of social media's grip on reviewing, Ferriss used Twitter and Facebook to ask for a review. "Rallying my readers," he called it. Within an hour, 61 had complied.
A few of his early reviews were written by people who admitted they had not read the book but were giving it five stars anyway because, well, they knew it would be terrific. "I am looking forward to reading this," wrote a user posting under the name mhpics.
A spokesman for Amazon, which published "The 4-Hour Chef," offered this sole comment for this article: "We do not require people to have experienced the product in order to review."
The dispute over reviews is playing out in the discontent over Klausner, an Amazon Hall of Fame reviewer for the last 11 years and undoubtedly one of the most prolific reviewers in literary history.
Klausner published review No. 28,366, for "A Red Sun Also Rises" by Mark Hodder. Almost immediately, it had nine critical comments. The first accused it of being "riddled with errors in grammar, spelling and punctuation." The rest were no more kind. The Harriet Klausner Appreciation Society had struck again.
Klausner, a 60-year-old retired librarian who lives in Atlanta, has published an average of seven reviews a day for more than a decade.
"To watch her in action is unbelievable," said her husband, Stanley. "You see the pages turning."
Klausner, who says ailments keep her home and insomnia keeps her up, scoffs at her critics.
"You ever read a Harlequin romance?" she said. "You can finish it in one hour. I've always been a speed reader."
She has a message for her naysayers: "Get a life. Read a book."
More than 99.9 percent of Klausner's reviews are four or five stars.
"If I can make it past the first 50 pages, that means I like it, and so I review it," she said. But even Stanley said, "She's soft, I won't deny that."
The campaign against Klausner has pushed down her reviewer ratings, which in theory makes her less influential. But when everything is subject to review, the battle is never-ending.
Ragan Buckley, an aspiring novelist active in the campaign against Klausner under the name "Sneaky Burrito," is a little weary.
"There are so many fake reviews that I'm often better off just walking into a physical store and picking an item off the shelf at random," she said.