Think the overly generous five-star rating of that god-awful burger joint in your neighbourhood is a bunch of bull? If Yelp suspects reviews are paid for, it will now post a warning sign.
Going forward, when Yelp discovers these acts of bribery, it will put up a red alert on that business's page. The scarlet letter of Yelp dirty dealings will stay there for 90 days. You often pull up the site and see these gushing reviews, and they make you suspicious.