SAN ANTONIO -

Local business owner Mark Mullis, of Lone Star Tile & Grout, said his business is taking a hit because the online review company Yelp has been filtering out his positive reviews.

"What their customer service folks are telling me on the phone is, 'Mark, we don't know that you're not actually putting those customer service reviews online yourself,'" Mullis said.

Yelp spokeswoman Kristen Whisenand told the Defenders that one of the Lone Star Tile & Grout reviews was written by Mullis.

As for the other seven positive reviews that have been filtered out, Mullis insists they are actual customers who are more than satisfied.

"I can verify with you. I can give you orders, work orders that are signed by the customer," Mullis said.

Customer Richie Valadez said Mullis requested he write a review, but only if he was happy with the work.

Valadez was pleased with the work done by Lone Star Tile & Grout, but unhappy with the way Yelp filters reviews, including the one he wrote himself.

"Reviews are great, they should be unfiltered -- both good and bad," Valadez said.

Out of nine Lone Star reviews, one is negative and it is the only one that is not filtered, resulting in a two-star review for Mullis' company.

Whisenand said Yelp uses an algorithm in an effort to filter out reviews that are not authentic. It is a strategy she said many of her customers appreciate.

She also explained the filtered reviews are accessible.

"There is a spot at the bottom that says, 'Click here for filtered reviews.' However, it also says, 'These reviews do not add any weight to the score," Valadez said.

Mullis also noticed Yelp began soliciting his advertising business several months back when his five-star rating dropped to two stars.

"They didn't say it out right, but they implied that if I paid them $400 or $500 a month to do paid advertising with them, that most likely we'll see the good reviews," Mullis said.

Whisenand insists the algorithms have nothing to do with advertising, but she did say businesses that pay for advertising will have their business placed above other listings in the same category.

She also noted is it not a perfect system, but with 84 million monthly visitors, it is a popular one.

For a list of recent stories April Molina has done, click here.