On 20 Jul 2018, Ed Cryer wrote in
alt.windows7.general:

I've used a technique with spam callers who start with something
like "Hello. And how are you today?"
It consists of completely monopolising the conversation. They're
paying for it; you can have a captive audience.

Oh, I'm feeling very down today. My dad died and left me all his
debts. And then my computer blew up, and shattered the house,
bringing down the partition wall with next door. And then an alien
flew in through the window, abducted me to a mother-ship in the
sky and implanted God knows what in me. I'm finding that I've
acquired extraordinary powers; such as I can fly like a bird, and
my eyes give out a beam of light which can cut through solid
objects like a laser beam, and there's a big S carved on my front,
and ... Hello, are you still there?

I used to toy with junk telemarketers until I realized that I was
wasting my own time, not theirs. But when I did, one of the most
effective tacks was to grab a book and start reading random sentances
from it at them in a conversational tone. It had the effect of
responding to their spiel with nonsense answers that sounded like they
should make sense. It rarely failed to keep them going for a good, long
time until they finally hung up in consternation.