BizSugar.com › Marketing › The growing influence of Yelp.com on small business

THE Rooz Cafe, a restaurant and coffee shop in Oakland, Calif., signals its distaste for patrons who post reviews on Yelp.com with a small sign: No Yelpers.

Rooz's owner, Steve Ranjbin, said he put the sticker up as a joke, but added that he had a complaint about Yelp.

“Yelp does not respect us as business owners,” Mr. Ranjbin said. “They don't listen to business owners unless you're an advertiser paying Yelp.”

Mr. Ranjbin, who said that amateur reviews can hurt his business, said some had misquoted him or called his employees names, but that Yelp had refused to take these comments down. Yelp rarely removes reviews, even when advertisers complain, preferring to let the crowd have its say.

The proliferating reviews of Mr. Ranjbin's establishment offer a good illustration of people's newfound love of comparing notes via reviews online.

According to Nielsen/NetRatings, 2.5 percent of all Internet users in March went to Yelp.com, and traffic there quadrupled over the last year. Yelp tracks its users through Google Analytics, and the company, which is almost four years old, said it had 9.5 million unique visitors in April, nearly double the 5 million it reported last October. There are more than 2.6 million reviews on the site.

“This site is having an impact on business,” said Greg Sterling, founding principal of Sterling Market Intelligence, a consulting firm that focuses on the Internet's effect on local consumer and advertiser behavior. Mr. Sterling said that Yelp had become an early leader in that field, which also includes Judy's Book and Insider Pages.