They are not "selling" anything they are "social engineering" (as a "nice way of saying it) anyone sad enough to interact with them and also noting the numbers that get any response (even an answering machine) like there is a live body on the other end so the number can be sold to other scammers.  Once identified and a possible source of a "mark" they are after the number like stink on DooDoo...

Did not answer

Jerks Spoofing 319 409-9739 With "Unavailable" As CID. Turds tried back in March - no Joy for them ;>  Then again in April - same dumped my the blockers result - Too Stupid to not waste their efforts - Hope it cost them money ;>

ESAD JOs

Time For a Nelson Muntz :  "Ha Ha !!!"

Same scum different Spoofed number  - 319 409-9739 Caller ID "Unavailable"
Their back !!!
After about a year of spoofing other numbers I guess...  They tried ~9 times and got bounced by my call blockers for every one...  Mental Midgets that just keep trying and get nothing.

Same turd callers with Spoofed number and CID, same Human Sewage in search of live phone numbers and people to try to defraud.

Don't feed the scum - don't interact with them - bait them/answer the phone/ etc. do any of those things and all you get are more calls from more of the same sort of human waste...

May they all ESAD JOs

Time For a Nelson Muntz :  "Ha ha !!!"

Called/ didn't leave message.  I never answer until I consult this site