grandpa - 11:40 pm on Jan 7, 2011 (gmt 0)
At least three large botnets have stopped sending spam. The theory is that they may be re-tooling. The nets still exist - they are simply inactive right now. A fourth botnet has been shut down. Source: [bbc.co.uk...] (same source cited by O.P.)
I have never understood those that buy from e-mail spam.
The human mind is a strange thing. I once witnessed a fellow fall for a lottery scam, all but certain that his investment would pay off big. No amount of persuasion would deter him. Finally, one day the check did arrive, and the bank took it away from him. I suspect he is still replying to any number of scams.