Hell, America represents the world's largest market of consumers, QED. If you blacklist a payment center for transactions from USA, then you've effectively crippled them. The end result will be that banks will not want to do business with spammers.
What will really hurt them will be if you can get Japan, the EU, the UK, and others on board with the program. Do that and it will make it very hard for anyone to make money through an obnoxious means.
What will really hurt them will be if you can get Japan, the EU, the UK, and others on board with the program. Do that and it will make it very hard for anyone to make money through an obnoxious means.