Freerice

For every question a user answers correctly, 10 grains of rice are donated via the United Nations World Food Programme (WFP).

The site was created by John Breen, a computer programmer, to help his son study for the SAT exam.

On November 20, 2007, the WFP launched a campaign to "feed a child for Thanksgiving", encouraging internet users "to take time out from traditionally the busiest online shopping period of the year and help the hungry" by playing the game.

[1] In September 2010, the UN World Food Programme launched a new version of the game with social networking, groups, rankings, and achievements.

One month after the inception of the viral marketing program, users had earned enough points for one billion grains of rice.