Shares of Facebook Inc. (FB), the world's largest social network, were up 10% in the first quarter, driven by improvements in consumer engagement and mobile monetization. We continue to believe that Facebook is in the early stages of building out its global advertising business. The company has an attractive customer base and stands to benefit from expected improvements in the price of advertising on its platform. Its recent acquisitions of Instagram and WhatsApp provide further growth opportunities and possible synergies with the Facebook network
From Baron Funds' first quarter 2014 commentary.