Spammers Make $200M A Year, Costs U.S. $20B
 

Researchers are claiming that spammers make roughly $200 million a year at a cost to the U.S. of $20 billion. We estimate that American firms and consumers experience costs of almost $20 billion annually due to spam. Our figure is more conservative than the $50 billion figure often cited by other authors, and we also note that the figure would be much higher if it were not for private investment in anti-spam technology by firms, which we detail further on.

http://www.hardocp.com/news/2012/08/..._costs_us_20b/