One of the bad ideas for dealing with spam that came up in the early days — not Canter & Siegel early, but not this millennium either, I'm pretty sure — was what I think of as Internet Postage Stamps:* charging a small fee for each recipient of every message you send. We all agreed it was a terrible idea, and IIRC it didn't gain much traction even among politicians and disappeared pretty quickly.
But every once in a while I get a piece of spam so idiotic that I find myself wondering if it was really such a bad idea, on the theory that if they had to spend even a penny per thousand, they'd go broke without finding enough morons to make it pay off, and the rest of us would have fewer reasons to think ill of our fellow humans, having been exposed to fewer reasons to wonder just how dumb a person can be.
This one arrived in my MIT inbox today (another testament to the expensive commercial spam filter the new "professional" MIT IS (whatever they're calling it this year) pays for):
We just got this from the irs. It is related to mit.edu. Please check it out asap. [-- Attachment #2: mit.edu_irs.doc --]
* Googling this would obviously be useless in 2016, even if what I call it in my head turned out to actually be what the proponents called it at the time. And I'm not interested enough in refreshing my memory about the history to try to come up with search terms that would be useful. But if any of you are that curious, please share what you find.