Anti-spam suggestion

I just responded to a post on the pretty cool www.threadwatch.org about spam. It gave me an idea for a way we could reduce spam:

Have a system that everyone agrees to that says in essence "If you want to send more than 1000 emails you have to sign up to a scheme that costs a few hundred a year, the profits of which go to charity"

You could be really strict on the extra measures or relaxed, I dunno, but it would reduce spam at no cost to users, little cost to legit companies and great benefit to charity. Its a lot less hassle than the standard pay-per-send anti spam measure.