Zynga brought in $445 million (£280.7 million), or 12 per cent, of Facebook's total revenue last year, the social network's IPO filing reveals.
The filing, from which Facebook seeks to raise $5 billion and could see the company valued at up to $100 billion, shows that total 2011 revenue was $3.7 billion - of which a billion was profit.
The vast majority of revenue, $3.1 billion, came from advertising. Facebook Payments brought in $557 million, though sales of virtual goods are growing rapidly: in 2010, the figure was $106 million.
"Facebook was not originally created to be a company," CEO Mark Zuckerberg, who will reduce his $500,000 annual salary to $1 in January 2013, wrote in the company's S1 filing. "It was built to accomplish a social mission - to make the world more open and connected.
"There is a huge need and a huge opportunity to get everyone in the world connected, to give everyone a voice and to help transform society for the future. The scale of the technology and infrastructure that must be built is unprecedented, and we believe this is the most important problem we can focus on."
Source: VentureBeat