Spammers make a combined $200 million a year while costing society $20 billion

. Spam emails are something Internet users just have to deal with. No matter how much companies spend to prevent spam, it doesn't seem to make it any less prevalent. According to a report from Justin Rao of Microsoft (MSFT) and David Reiley of Google (GOOG), spammers and spam-advertised merchants cost society a whopping $20 billion while gaining a mere $200 million in combined revenue per year. The “externality ratio” of external costs to internal benefits for spam is around 100:1.

Boy Genius Report , Spammers make a combined $200 million a year while costing society $20 billion, Spammers make a combined $200 million a year while costing society $20 billion