LinkedIn ( LNKD) went public back in the summer of 2011, joining a cadre of social media IPOs that hit the market around the same time. LinkedIn, though, is the sole survivor of the battle for investor dollars; since going public, the firm has rallied 30%, making it one of the few social media names that hasn't lost investors money from the get-go. A big part of that has to do with LinkedIn's business. While other social media firms earn revenues by distracting their users from what they're trying to do (and getting them to click on ads while stalking their friends, for instance), LNKD makes money by helping users with the exact task they're trying to accomplish: find a job, network, or hire someone. That seems like a small distinction, but it's critical to LinkedIn's ability to make money off of each user. The historically high employee turnover we've seen in recent years makes LinkedIn a must-use product, particularly in an environment where traditional job websites are being seen as less and less useful. LinkedIn sports a big user base that gives it a hefty economic moat. New potential competitors can't merely hang up a shingle and expect the type of user engagement that LinkedIn enjoys. That fact should keep rivals at bay. The firm's spotless balance sheet includes close to $700 in cash and no debt, a solid position to enter 2013 on. While this stock is no value name either, its trajectory warrants jumping onto shares ahead of Feb. 7 earnings.