With Tesla's race to new highs in recent weeks, I've found myself wondering when a potential Rule Breaker can be considered overvalued. Yelp (NYSE:YELP) might finally be getting close.

Look at the numbers. Yelp stock has more than tripled year-to-date, far outpacing the 68% revenue growth the company has achieved in each of the past two quarters. Improving usage data has investors betting big on Yelp's Rule Breaking potential.

YELP Total Return Price Chart

YELP Total Return Price data by YCharts

I can appreciate their optimism. Cumulative reviews jumped 41% last quarter as active local business accounts grew 62%. All told, Yelp now serves more than 108 million monthly visitors, with a growing number coming from mobile devices. (The company says every second a consumer uses a Yelp mobile app to call a local business or generate directions.)

We could see even better numbers soon. Last week the company introduced on-the-go reviews in a revised Android app. A new iOS version sports improved navigation and other "polish," such as better scrolling and animated icons.

I'm glad to see the updates, especially on Android. Yelp may be hugging Apple, but Google's Android still powers hundreds of millions of millions of devices around the world. That's a huge addressable market that Yelp needs to do a better job of winning. I won't be buying till I see evidence that it has.

Do you agree? Would you buy Yelp stock at current prices? Leave a comment to let us know what you think.

Fool contributor Tim Beyers is a member of the Motley Fool Rule Breakers stock-picking team and the Motley Fool Supernova Odyssey I mission. He owned shares of Apple and Google at the time of publication. Check out Tim's Web home and portfolio holdings, or connect with him on Google+Tumblr, or Twitter, where he goes by @milehighfool. You can also get his insights delivered directly to your RSS reader.

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