Social media and Wall Street have long had an awkward relationship. For some time, investors have been aware of the power and influence of Web-based media, but how they can profit from it has been less than clear. But when Yelp debuted on the NYSE in March, investors cheered, sending the stock up 64% on the first day of trading. Yelp has had its share of troubles since then: some investors have worried about the firm’s strategy to grow revenue from mobile users, while others remain loyal because they like the company’s business model of extracting advertising revenue from the very businesses that consumers are using the service to learn about. As Kendall Whitehouse, director of new media at the University of Pennsylvania’s Wharton School, says, “One of the things that is attractive about Yelp is the site’s closeness to the user’s purchase decision. Someone looking up a restaurant review in Yelp is very likely planning to go out to eat somewhere. And that should be easy to monetize.”