Chart - Worldwide Facebook Revenues By Source, 2009-2013

Paid advertising accounts for the vast majority of Facebook’s total revenue, though its share has been dropping over the past several years. As recently as 2009, advertising accounted for 98% of the company’s intake; this year that percentage is down to 83.9%. Total revenues at Facebook will break the $5 billion mark this year, an increase of 35.9% over 2011. Read the rest at eMarketer.