Facebook unveils new friends-based search tool MENLO PARK, California (Reuters) - Facebook Inc CEO Mark Zuckerberg unveiled on Tuesday a feature to help its users search for people and places within the social network, in the company's first major product launch since its May initial public offering. Speaking to reporters at its Menlo Park, California headquarters, Zuckerberg revealed "graph search," which allows users to sort through only content that has been shared with them - addressing potential privacy concerns. Available as a beta or early version to hundreds of thousands of users now, the new feature - dubbed "graph search" because Facebook refers to its growing content, data and membership as the "social graph" - will initially let users browse mainly photographs, people, places and members' interests, he added. Zuckerberg promised users will be able to tailor their searches, such as by specifying music and restaurants that their friends like, or their favorite dentist. The reverse is also possible, such as discovering friends who have an interest in a particular topic. Facebook may explore ways to earn revenue off of the service in the future, he added. "You need to be able to ask the query, like, who are my friends in San Francisco," Zuckerberg said. Graph search is a really big product. It's going to take years and years to index the whole map of the graph and everything we have out there. We'll start rolling it out very slowly. We're looking forward to getting it into more people's hands over coming weeks and months. Critics have long deemed the social network's current search capabilities inadequate. Zuckerberg stressed Facebook was not getting into Internet searches, Google Inc's specialty. But the news drove shares in Yelp Inc, which focuses on pooling customer reviews of restaurants and other popular services, about 7.1 percent lower. Wedbush Securities analyst Michael Pachter argued that recommendations from trusted friends were more valuable than from strangers on the Web. "The initial focus is on getting users more engaged, so this is making Facebook more useful and sticky," Pachter said. I don't see a revenue model initially, but think ultimately, search makes user activity even more relevant to advertisers, and allows greater focus. The world's largest online social network, with more than one billion users, Facebook is moving to regain Wall Street's confidence in the wake of a rocky IPO and concerns about its long-term money-making prospects. Central to its efforts is devising new ways to make money from users who are migrating to mobile devices. Zuckerberg said the company is working on that front. Speculation approached fever pitch over the past week about what Facebook planned to reveal in its highest-profile news briefing since its market debut. Guesses had ranged from a long-rumored smartphone to a full Web-search product. That anticipation, as well as expectations of strong fourth-quarter financial results, helped boost Facebook's stock. Its shares are up more than 15 percent since the start of the year. On Tuesday, its stock slid 2 percent at $30.30, giving up some of its recent gains. "The search function on Facebook was basic and as such, a wasted opportunity given Facebook's imperative to strengthen advertising revenues," said Ovum Research analyst Eden Zoller. Zuckerberg said he could foresee a business in search over time, but analysts advised caution. Facebook has come under fire numerous times for unclear privacy guidelines. Facebook graph search will no doubt leverage member data to provide advertisers with more targeted, personalized advertising opportunities going forward. But Facebook needs to tread very carefully here and be mindful of user privacy," Zoller said. Reporting by Alexei Oreskovic in Menlo Park; Additional reporting by Malathi Nayak in San Francisco and Himank Sharma in Bangalore; Writing by Edwin Chan; Editing by Phil Berlowitz