If SpamCop is so great, why is there still spam?
My own experience is that SpamCop lost their fire after the Cisco acquisition. As far as the spammers are concerned, SpamCop is just another minor nuisance to live with.
To really reduce the spam, the spammers' business models must be broken. As long as they are making money, they will continue to spam. Case in point: How much stock market pump-and-dump spam do you see now? Almost none, because the spammers' business models were targeted and shut down--but only after several academic reports showed the spammers were basically printing money there.
I wish ANY of the major email providers would take the initiative of creating really effective anti-spammer tools to allow US, the extremely annoyed masses, to break the spammers' business models. Look at the numbers. The suckers who actually feed the spammers are a relatively rare and precious resource. Such profound stupidity doesn't grow on every tree. You don't have to help, but I sure wish I could help categorize the spam and target the best countermeasures to cut the spammers away from the suckers.