Since C&W sold it's US mail server business and SpamHouse wrote to the new owners about the power of rumour in the stock market and the effect on shares in all their businesses I found that overnight the level of spam dropped from hundreds per day to nothing. The new owner went public in in a big way about how they were "transitioning" the business. (Huh?)
The spammers then started using their brains eg connected me with an address because of where I store web pages. They are not getting smarter - but they are learning or loosing business to the point of failure.