From an overview of Facebook, the social data management company
At the moment, the battle is on between those two models of making money from online advertising. If Google’s search engine cast the Internet as an instrument of solitary exploration, Facebook requires its users to share what they do with their Facebook “friends.” In some ways, the Facebook offering is a test of how valuable the social model of the Internet could be.
According to comScore, a market research firm, Facebook has become the largest platform for display advertising on the Web in the United States; 28 percent of all display ads come to Facebook, followed by Yahoo, which gets less than half that share.
While advertising is its bread and butter, Facebook has sought new sources of income by becoming a place where goods and services are bought and sold, whether it is virtual farm animals or real concert tickets.