Ed Wells, who runs a Florida restaurant called Chowder Heads, is concerned that negative Yelp reviews may be hurting his business. The restaurant has a two-star rating on the site, and he says some positive reviews have been filtered out. Other business owners have said Yelp rewards those who buy ads with better ratings. Yelp spokeswoman Kristen Whisenand defended the company's practices. "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," she said.