...

you could bet that by closing off this avenue, SPF will force spammers to use other methods that are more easily detected / filtered, and that if you play this cat&mouse game long enough, it will drive the cost of spam so high (or drive the volume benefit so low) that it'll just die out.

Good summary. This is the right strategy.

on the contrary. it has been a bad strategy and is still a bad strategy.

...

but to me, SPF is just a way to rearrange the deck chairs on the Titanic.

I can swim but I believe that the water under the Titanic was quite too cold to stay. Any advice to the people on the NANOG mailing list before the boat goes down?

the boat will never go all the way down -- the internet, and e-mail, are "survivable". however, it will get very cold where you are, since you'll be floating in atlantic icewater while clinging to floating wreckage. if that fate does not appeal to you, then embrace change. specifically, the kind of change that makes you cringe in fear because it is so alien. i'm referring to whitelists, webs of trust, trusted introducers, micropayments, and bonding. if you insist on an inbox that's open to all comers no matter what their intentions or reputation, then get out your snorkle.