Social reviewer Yelp (NYSE:YELP) is up huge so far this year, recently topping the $50 per share threshold. Much of the investor optimism is due to mobile revenue growth, but the company still faces threats from larger rivals like Google (NASDAQ:GOOGL), who tried to acquire Yelp years ago. As Yelp transitions to mobile, it will rely less on Google for traffic, which is a good thing.

In the following video, Fool contributor Evan Niu, CFA, and Eric Bleeker, CFA, discuss why Yelp has had such a good year, and whether or not the current valuation makes sense.

Eric Bleeker, CFA, has no position in any stocks mentioned. Fool contributor Evan Niu, CFA, has no position in any stocks mentioned. The Motley Fool recommends Facebook and Google. The Motley Fool owns shares of Facebook and Google. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.