Yelp announced today that it is now showing warnings to users when they have found businesses that have paid for reviews. If you are looking at such a business on the site, you’ll be greeted with a “Consumer Alert”. This comes with a message that says:

“We have caught someone red-handed trying to buy reviews for this business. We weren’t fooled, but wanted you to know because buying reviews not only hurts consumers, but also honest businesses who play by the rules. Check out the evidence here.

Yelp will remove the alert from the business’ page after 90 days, unless they find more efforts to mislead consumers. Yelp indicates that nine businesses will have the alert showing up at launch, but it will appear on any other pages for businesses Yelp finds to be in violation.

Yelp says its automated review filter is “working around the clock” to flag these kinds of reviews.

Eric Singley, Yelp’s VP of Consumer Products and Mobile, says, “As efforts to game the system continuously evolve, so do our methods for combating it. An independent Businessweek report confirmed the success of Yelp’s efforts to protect consumers. The article details the efforts of a Texan business owner who purchased 200 online reviews in an attempt to artificially bolster his business’s online reputation. The report found that Yelp’s review filter returned ‘impressive results’ catching every purchased review, while the shill reviews remained up on seven other review sites.”

“Beyond alerting consumers to attempts to purchase reviews, the next step will be to let consumers know if a business has had a large number of reviews submitted from the same Internet Protocol (IP) address, which can be a helpful indicator that they lack authenticity,” he adds. “While the review filter already takes this type of information into account, we believe that consumers also have a right to know if this activity is going on.”

He does reassure users that most businesses on Yelp are playing by the rules.