said by dave:That seems to be a poor strategy: targetting people who've already said they don't want to talk to you, and hoping that they want to talk to you.
Statistically unlikely to do better than random dialling, I'd suppose.
This is just a guess, but: I suspect that a fair number of people on the DNC registry are elderly folks who have had their numbers registered
for them by relatives who understand just how susceptible the elderly can be to people with whom they talk (even over the telephone).
The sound of a human voice can count for a
lot with some people, even if the voice in question is connected to a brain whose only intention is to sell you things you don't need and can't really afford.