Cutting off the revenue stream of spammers

I’ve always wondered why spam could not be prevented by educating the public to not purchase things advertised in spam emails. A study mentioned in a New York Times article follows a similar train of thought: By stopping banks from accepting money for spam offers, one could destroy the revenue stream of spammers. Quote:
It turned out that 95 percent of the credit card transactions for the spam-advertised drugs and herbal remedies they bought were handled by just three financial companies — one based in Azerbaijan, one in Denmark and one in Nevis, in the West Indies.
If a handful of companies like these refused to authorize online credit card payments to the merchants, “you’d cut off the money that supports the entire spam enterprise,” said one of the scientists, Stefan Savage [...]

“In the end, spam is an advertising business,” Dr. Savage said in an interview. “However, it only makes sense if you can find a way to take people’s money.

To globally receive money, you need to rely on credit cards, but their use is already heavily controlled. Thus, it would be relatively difficult for spammers to switch banks if their current ones terminated their contracts. That is, this non-digital part of the spam equation provides a low-cost way of fighting spammers that they cannot easily circumvent.

The article also describes the scale and economies of spam:

An earlier study undertaken by the scientists showed that a single commercial spam e-mail campaign generated three messages for every person on the planet. That same study revealed that to sell $100 worth of Viagra, a spam provider needed to send 12.5 million messages.
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