Market for spam

The BBC, reporting on the work of Stefan Savage, director of UCSD's Collaborative Center for Internet Epidemiology and Defenses, says that the number of sales generated by spam are surprisingly small, so that spam networks might be vulnerable to measures that would increase their costs even slightly: Study shows how spammers cash in

Savage's study involved sending his own spam, he must have had an interesting conversation with UCSD's Institutional Review Board (i.e. human subjects committee...)