Originally Posted by tofu

If it were possible to charge for email, how much would the cost have to be to deter spammers? Can anyone think of any way to put a lower bound on it?

What I'm getting at is, I think that almost any cost would put a stop to the run-of-the-mill spammers, the people selling Viagra. I believe they have to send a million email in order to make a single sale. So the cost could be as low as 1/4 of a penny per email and that would mean it costs them $2,500 to send spam. That would put them out of business. So I wonder just how low of a charge would still work. 1/10th of a penny?

But what about the stock spammers? I linked to a study in a previous spam thread that showed that stock spammers always make about 6% profit. So for them, no charge for email would be deterrent so long as they had enough cash invested so that the 6% profit covered the cost of the email. For example, if they could invest $42,000 in the stock, then they would make $2520 after sending the spam - enough to cover the cost of a million spam messages.

Do you think that the stock spammers have that kind of money?