According to the NYTimes, web retailers are scrambling for online opinions and happy 5-star reviews — now that we shoppers are increasingly using the judgment of Anonymous Guy from Somewhere I Don’t Know in helping us choose which books or appliances to buy, which tickets to snag or where to stay when we travel.

Inevitably, a kind of grey market has arisen. Freelancers are churning out raves-for-rent while companies go trolling for positive reports-from-the-field. And then there are the business rivals posting negative attacks.

Apparently, the “wisdom of crowds” can be bought for $5 to $10 — which gives new meaning to all those stories the past several years  crying or crowing about the death of the professional critic and the rise of the digitally empowered audience.  Mostly, it seems, the definition of “professional” was just scaled downward.

And now countermeasures are being considered.

“For $5, I will submit two great reviews for your business,” offered one entrepreneur on the help-for-hire site Fiverr, one of a multitude of similar pitches. On another forum, Digital Point, a poster wrote, “I will pay for positive feedback on TripAdvisor.” A Craigslist post proposed this: “If you have an active Yelp account and would like to make very easy money please respond.”

The boundless demand for positive reviews has made the review system an arms race of sorts. As more five-star reviews are handed out, even more five-star reviews are needed. Few want to risk being left behind.

Sandra Parker, a freelance writer who was hired by a review factory this spring to pump out Amazon reviews for $10 each, said her instructions were simple. “We were not asked to provide a five-star review, but would be asked to turn down an assignment if we could not give one,” said Ms. Parker, whose brief notices for a dozen memoirs are stuffed with superlatives like “a must-read” and “a lifetime’s worth of wisdom.”

Determining the number of fake reviews on the Web is difficult. But it is enough of a problem to attract a team of Cornell researchers, who recently published a paper about creating a computer algorithm for detecting fake reviewers. They were instantly approached by a dozen companies, including Amazon, Hilton, TripAdvisor and several specialist travel sites, all of which have a strong interest in limiting the spread of bogus reviews.

So perhaps it’s not a “grey” market, given that no real legal line is being crossed. A pewter tint, perhaps — no, I’d say a smoky chiaroscuro, with extra points going to everyone’s neo-classic (and capitalist) impulse to game the system. We’re returning reviewing to the 18th century tradition of actors often hiring their own claques to cheer their performances (claque comes from the French for “clapping”).