On Wednesday, social review site Yelp (NYSE:YELP) released its earnings report, and investors were pleased as punch. Some of the company's biggest gains came from the mobile side of its business -- but will that be enough to fend off its competitors? After all, Facebook's (NASDAQ:FB) quickly catching up with mobile advertising, while Google (NASDAQ:GOOGL) still has Zagat and the most popular mobile OS up its sleeve. Check out the video below to hear blog editor Mark Reeth talk about what Yelp is doing to keep the competition at bay, and if it can survive the dog-eat-dog world of mobile.