I've placed on behalf of Facebook a few more bounties on D-related issues.
There are interesting research done on such topics: http://freakonomics.com/2013/06/05/is-paying-for-blood-a-good-idea-after-all/1
In Freakonomics, we mentioned Richard Titmuss‘s landmark 1970 study on blood donations, which found that offering money for blood actually hurt donations.<
Bye, bearophile
