Second in the series this week about free goods: how to enrich your vocabulary and provide food relief, both for free. FreeRice provides a vocabulary test, and for each answered questions provides some grains of rice to needy people.
How can this be pulled off? After all the website operators need to maintain a server, databank and buy bandwidth and rice. It is all financed by discreet ads at the bottom. So discreet in fact that I did not notice them until I saw them mentioned in the site's FAQ. Cost are relatively low, however: 1000 grains of rice cost in the order of one cent (wholesale), and the marginal cost of server traffic is close to zero.
This site has become a favorite in many schools, and these few grains a word certainly add up. As of today, the total is closing in on 25 billion grains, and their cost still add up to a quarter million dollars.