In the fall of 2010, Mr. Rutherford started a Web site, GettingBookReviews.com. At first, he advertised that he would review a book for $99. But some clients wanted a chorus proclaiming their excellence. So, for $499, Mr. Rutherford would do 20 online reviews. A few people needed a whole orchestra. For $999, he would do 50.
There were immediate complaints in online forums that the service was violating the sacred arm’s-length relationship between reviewer and author. But there were also orders, a lot of them. Before he knew it, he was taking in $28,000 a month.
A polite fellow with a rakish goatee and an entrepreneurial bent, Mr. Rutherford has been on the edges of publishing for most of his career. Before working for the self-publishing house, he owned a distributor of inspirational books. Before that, he was sales manager for a religious publishing house. Nothing ever quite worked out as well as he hoped. With the reviews business, though, “it was like I hit the mother lode.”
Reviews by ordinary people have become an essential mechanism for selling almost anything online; they are used for resorts, dermatologists, neighborhood restaurants, high-fashion boutiques, churches, parks, astrologers and healers — not to mention products like garbage pails, tweezers, spa slippers and cases for tablet computers. In many situations, these reviews are supplanting the marketing department, the press agent, advertisements, word of mouth and the professional critique.
But not just any kind of review will do. They have to be somewhere between enthusiastic and ecstatic.
“The wheels of online commerce run on positive reviews,” said Bing Liu, a data-mining expert at the University of Illinois, Chicago, whose 2008 research showed that 60 percent of the millions of product reviews on Amazon are five stars and an additional 20 percent are four stars. “But almost no one wants to write five-star reviews, so many of them have to be created.”
Consumer reviews are powerful because, unlike old-style advertising and marketing, they offer the illusion of truth. They purport to be testimonials of real people, even though some are bought and sold just like everything else on the commercial Internet.
Mr. Liu estimates that about one-third of all consumer reviews on the Internet are fake. Yet it is all but impossible to tell when reviews were written by the marketers or retailers (or by the authors themselves under pseudonyms), by customers (who might get a deal from a merchant for giving a good score) or by a hired third-party service.
On the internet, everyone knows you’re a dog.

