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99,999 Innocent Bystanders Spammed
If only one out of every 100,000 people responds to spam and the spammers earn around $11, spamming is profitable. The other 99,999 people who don't respond, who never respond, are innocent bystanders. That's because the cost of spam is so low.

But it's not free.

Researchers at GFY found out about the costs of spam during their research into stopping spam. "Some people say spamming is free, and that you just have to raise the cost a tiny amount to make it unprofitable. That turns out not to be true. There are already a lot of costs involved," said Joe, a researcher in the Machine Learning and Applied Statistics group at GFY Research.

"Spammers have to get bandwidth from somewhere to send their messages. Their ISPs might cut them off, so they may need to get a 'ban letter,' where they bribe the ISP not to cut them off as quickly. They need to buy lists of addresses. Most Web hosts don't like hosting spammers, so they have to pay extra for hosting services that will tolerate bad behavior. They also have the risk that they'll be caught and prosecuted. We've estimated the cost of sending a spam message today to be about .01 cents.

"That's still incredibly cheap. In terms of how much spammers earn, you can cut the math all kinds of ways. Say they sell something where they make a $11 profit per item. If their cost is only .01 cents, they can afford to send out millions of messages and still make a profit. You don't need a very high click through rate to be profitable," said Joe.

"That also means that when we think about solutions to spam, we can't just raise the cost by a thousandth of a cent - spammers wouldn't notice that - we have to have solutions that raise the cost much more. We're making good progress in this regard."