Ed Wells, owner of Chowderheads restaurant in Jupiter, Florida. Courtesy Ed Wells A restaurant manager told us that his two-star rating on Yelp is ruining his business.

Ed Wells helped open Chowderheads in November, and says he's built up a legion of regulars since then. But he worries that because of Yelp, some potential customers never make it through the door of his Jupiter, Fla. restaurant.

"It's very scary as a restaurant because I'm sure people avoid coming here because of the rating," Wells told us. "The customers who do come in ask me about why the rating is so low."

Wells also says that a Yelp representative cursed him out after he declined to buy advertisements from the site.

He complained and later received an apology. But shortly after the incident, Wells said bad reviews started pouring in, such as this one from a man identified as Bob P.:

Wells also cited the many positive reviews on Yelp, many of which are filtered through the company's screening system.

Yelp says it filters reviews that are suspicious, such as ones coming from the same IP address that could have been written by the same person. The system favors frequent posters.

The company won a lawsuit earlier this year demanding that it reveal its filter criteria. For now, the exact reasons reviews are filtered are a secret.

Yelp made headlines this week after a California restaurant made a sign alleging that Yelp representatives told owners that if they wanted a higher rating on the site, they should buy ads.

Kristen Whisenand, a Yelp spokeswoman, said the company does not favor advertisers over anyone else.

"I want to make it clear that there has never been any amount of money a business can pay Yelp to manipulate reviews, nor does our automated review filter 'punish' those who don't advertise," Whisenand said. "The filter works the same for both."

But Wells, and other small business workers, feel that Yelp unfairly penalizes smaller companies over larger ones.

Business consultant Adyenn Ashley wrote on her blog that she gets tearful calls from small business owners every week.

"Feeling helpless, alone, attacked, the emotion coming through the phone line sounds a lot like the rape victims I counseled in college," Ashley writes. "The same questions: How did this happen? Why me? And worse, why won’t anyone help me?"

She started a website, Yelp-Sucks.com, that encourages small business owners burned by Yelp to leave their stories.

Whisenand pointed out that small businesses with higher reviews could get customers and exposure they normally wouldn't. The company also lets business owners respond to customer reviews.

But Wells said that the risks of Yelp far outweigh the benefits for businesses like his.

"I often talk to other business owners who are going through what I am," Wells said. "People aren't going to look up a review for the big chains, they're going to look up reviews for smaller places they haven't heard of."