The question for investors is whether or not the company will be able to increase revenues in the future. While it seems unlikely that Facebook would ever outright charge users for its services, it may begin to offer small services for a fee. The company recently demonstrated such a move in New Zealand, allowing its users to purchase increased visibility for their status updates at a small cost. Facebook has also moved to become more aggressive in its approach to advertising, altering its privacy settings and allowing advertisements to appear in users' news feeds. Although these changes do not appear to have threatened Facebook as of yet, it isn't hard to foresee how further moves could discourage users and make them open to switching. With so much tied to personal accounts, users may be resistant to abandoning Facebook for another service. However, it wouldn't be without historical precedent -- Facebook stole much of Myspace's user base by offering a superior service.