Spam mail, why is it still used?

Back when e-mail first became popular, it was my great hope that spam mail would eventually be killed off entirely. However ... nope. Both physical and electronic forms of spam mail are still as common as before and possibly even more so. Why? Do people respond well enough that the marketers feel this is still a workable effort? I just can't see it. I suspect there's less chance of a snowflake surviving in Death Valley than there is of people acting on an unsolicited piece of mail.

Electronic spam filters have become very sophisticated and eliminate tons of spam, yet some inevitably sneak through. So, they get deleted by us immediately. Again, why do spammers bother sending them out? Or, is it all a robot conspiracy and the internet is already sentient and attacking us? That's gotta be it, right? No human could possibly be that diligent. It must be machines!

So, it's now a race for human beings to overcome our new electronic overlords. Shut off those computers, throw away your cell phones, and only do things by candle light ...

NOPE!

I believe I'll just roll my eyes, toss away the junk and hit the delete button.

- M