$16 million raised by more than 500,000 individual donations during
seventh annual giving campaign
In just 50 days, the shortest fundraiser in Wikimedia history, the
Foundation received an average of $22 per individual donation from
people living in about 140 countries, to reach its goal.
This article gave me an inspiration to think that the ultimate product
price for an information product (pdf file) is suppose to be a 22$ per
item, because this is the average price that people who surf the web
and search for an information are willing to pay in a spontaneous urge
to pay online.
http://wikimediafoundation.org/wiki/Half_a_Million_People_Donate_to_Keep_Wikipedia_Free